\ 


THE  LIBRARY 

OF 

THE  UNIVERSITY 
OF  CALIFORNIA 


PRESENTED  BY 

PROF.  CHARLES  A.  KOFOID  AND 
MRS.  PRUDENCE  W.  KOFOID 


THE  LIBRARY  OF  ENTERTAINING  KNOWLEDGE. 


INSECT 


TRANSFORMATIONS. 


BOSTON  : 

LILLY   &  WAIT,    (late  WELLS  #  LILLY,) 

.tfG.tf  H.  Carvill,  and  E.  Bliss,  New-York;  Carey  ^  Hart,  Philadel- 
phia ;  W.  4-  J.  Neal,  and  E.  J.  Coale,  Baltimore  ;  P.  Thompson  $  Ho- 
mans,  Washington  ;  R.  Cruikshank,  Georgetown  5  W.  M.  Morrison, 
Alexandria;  R.  D.  Sanxay,  Richmond;  C.  P.  M'Kennie,  Charlottes- 
ville  ;  W.  H.  Berrett,  Charleston,  S.  C.;  Salmon  Hall,  Newbern,  N.C.  ; 
Mary  Carroll,  New-Orleans  ;  Odiorne  &  Smith,  Mobile  ;  .7.  P.  Ayres 
Nashville,  T.  ;  N.  4-  G  Guilford,  Cincinnati  ;  Little  $•  Cummings,  Al- 
bany; H.  Howe,  New  Haven;  H.  ^  F.  J.  Huntington,  Hartford;  S.  But- 
ler &  Son,  Northampton  ;  Whipple  $•  Lawrence,  Salem  ;  Eli  French, 
Dover;  H.  S,  Favor,  Eastport;  and  S.  Colman,  Portland. 


1831. 


CONTENTS.      •  / 

i  v>  ^  i  - 

SECTION  I.— EGGS  OF  INSECTS, 

CHAPTER  I. —INTRODUCTORY. 

Page 

All  insects  come  from  eggs,  1 

Curious  experiment  of  Kircher,  2 
Virgil's  receipt  for  making  a  swarrn  of  bees, 

Origin  of  these  ancient  errors,  4 

Bees  in  Sampson's  lion  accounted  for,  7 

Fancies  of  Robinet  and  Darwin,  9 

Theory  of  spontaneous  generation,  10 

Popular  errors  respecting  blight,  11 

Dr  Good's  account  of  blight,  12 

No  insect  eggs  afloat  in  the  air,  14 

Specific  gravity  of  insect  eggs,  15 

Theoretical  accounts  of  honey-dew,  16 

Accounted  for  by  experiments,  18 

Instantaneous  appearance  of  insects,  19 

The  f  worm  i'  the,  bud'  traced  to  its  egg,  20 

Insectiferous  winds,  22 

Supposed  shower  of  frogs,  snails^  &c,  23 

Diffusion  of  the  seeds  of  plants,  24 

Insects  jet  out  their  eggs  from  fear,  25 

Origin  of  mosses  on  walls,  27 

Origin  of  mould  in  the  heart  of  an  apple,  30 

CHAPTER  II. 

Physiology  of  insects' eggs,  33 

Theory  of  colours  meant  for  concealment,  ib. 

Disproved  in  the  case  of  the  eggs  of  birds,  34 

Illustrated  from  insect  eggs,  35 

Cause  of  the  colours  in  eggs,  36 

Structure  of  insects'  eggs,  38 

Eggs  of  ants,  spiders,  and  glow-worms,  39 

Form  of  insect  eggs,  40 

Cause  of  the  oval  form  in  birds'  eggs,  41 

Sculpture  of  the  eggs  of  insects,  ib. 

Curious  appendages  to  eggs,  43 

Eggs  with  foot  stalks,  46 
Number  of  irisect  eggs,  and  their  fecundity,  compared 

with  other  animals,  46 

CHAPTER  III. 

Maternal  care  of  insects  respecting  their  eggs,  49 

Instanced  in  a  carpenter  bee  (Chelostoma),  50 

Ichneumons  compared  to  the  cuckoo,  52 

Proceedings  of  a  solitary  bee  (Halictus),  53 

Stratagems  of  a  solitary  wasp  (Cereem)j  54 


M368511 


iv  CONTENTS. 

Ovipositor  of  an  ichneumon  (Pimpla),  56 

Experiments  of  Reaumur,  57 

Common  mistakes  of  Naturalists,  59 

Parasite  of  the  cabbage  caterpillar  (Pontia)> 

Egg  parasites, 

Parasites  of  the  aphides, 

Singular  parasite  of  the  cock-roach, 

Rare  parasites  of  bees  and  wasps,  67 

Tact  of  insects  in  discovering  food  for  their  young,  68 

Sometimes  select  exotic  plants,  69 

Instanced  in  a  leaf-miner  (Tephritis?),  70 

Solitary  and  gregarious  caterpillars,  71 

Life-boat  of  eggs  constructed  by  the  gnat,  72 

Experiments  upon  it, 

Infallibility  of  instinct  questioned,  76 

Mistakes  of  instinct,  77 

CHAPTER  IV. 

Hybernation  of  insects'  eggs,  79 
Proceedings  of  the  gypsey  moth  compared  to  the  eider 

duck,  ib. 

Singular  groups  of  eggs,  81 

Protection  of  eggs  from  heat,  83 

Anal  tweezers  of  moths,  84 

Eggs  in  spiral  groups,  85 

Arched  form  of  the  lackey  moth's  eggs,  86 

Hybernation  of  the  eggs  of  aphides,  87 

Singular  protection  of  the  eggs  of  cocci,  88 

Coccus  of  the  hawthorn,  90 

Shell-formed  coccus  of  the  currant,  92 

Hybernation  of  spiders'  eggs,  93 

Curious  spider's  nests,  94 

Eggs  of  the  vapourer  moth  on  its  cocoon,  95 

Effects  of  (fold  on  insects'  eggs,  96 

Observations  of  John  Hunter,  98 

Insects  not  killed  by  severe  frosts,  ib. 

CHAPTER  V. 

Hatching  of  insect  eggs,  100 

Structure  of  the  eggs  of  birds,  ib. 

Insects  do  not  hatch  their  eggs,  101 

Anomalous  instance  of  the  earwig,  102 

Earwigs  cannot  get  into  the  brain,  103 

Partial  hatching  by  spiders,  104 
Experiments  upon  the  wolf  spider  by  Swammerdam 

and  Bonnet,  105 

Eggs  hatched  before  they  are  laid,  108 

Ovo-viviparous  insects,  509 

Coil  of  larvae  in  the  body  of  a  blow-fly,  110 
Aphides  sometimes  produce  eggs,  sometimes  young,         112 


CONTENTS.  V 

Page 

Care  taken  of  these  eggs  by  ants,  113 

Cocco-viviparous  flies  (Hippoboscidaz),  116 

Effects  of  heat  upon  eggs,  118 

Management  of  silk-worms'  eggs,  120 

Effects  of  light  on  eggs,  ib. 

Some  insect  eggs  increase  in  size,  121 
Growth  of  the  eggs  of  ants, 
Developement  of  the  eggs  of  spiders, 

Spiders  live  long  without  food,  124 

Insects  probably  gnaw  through  their  egg-shells,  125 

Valves  of  insect  eggs,  126 

Period  of  hatching  influenced  by  temperature,  127 
SECTION  II.— LARVAE. 

CHAPTER  VI. 

Structure  of  caterpillars,  grubs,  and  maggots,  128 
Meanings  of  these  terms,                                            Note,  ib. 

Supposed  transmutation  of  plants  into  animals,  129 

Observations  of  Unger  upon  this,  130 
Remarks  of  Bory  St  Vincent, 

Supposed  formative  power  of  the  blood,  132 

Embryo  butterfly  in  the  caterpillar,  133 

Experiments  to  show  this,  134 

Dissections  of  the  buds  of  plants,  136 

Difference  of  plants  from  insects,  137 
Internal  structure  of  caterpillars, 

Breathing-tubes  and  formation  of  their  blood,  139 
Colours  of  caterpillars  not  intended  for  concealment,     140 

Imitative  forms  of  caterpillars,  142 

Walking-leaf  insect,  144 

Caterpillars  in  form  of  branches,  146 

Conspicuously  coloured  caterpillars,  147 

Butterflies  supposed  to  be  coloured  like  flowers,  149 

Singular  forms  of  caterpillars,  151 

Forms  of  water-grubs,  154 

Breathing  organs  in  water  larvae,  156 

Water  worms  (Nais)  may  be  mistaken  for  larvae,  159 

Syringe  for  respiration  in  a  water  larva,  161 

Curious  mask  of  the  same  larva,  163 

Dust  mask  of  the  wolf  bug  (Reduvius),  165 

CHAPTER  VII. 

Growth,  moulting,  strength,  defence,  and  hybernation  of 

larvae,  166 

Progressive  increase  of  the  silk-worm,  167 

Compared  with  the  growth  of  buds,  168 

Process  of  moulting  or  casting  the  skin,  169 

Accidents  interrupt  this  process,  170 
Reds,  a  disorder  similar  to  renal  gravel, 

Position  of  the  hairs. in  moulting,  173 
VOL.  VI.                               B 


VI  CONTENTS. 

Page 

Casting  of  the  interior  lining  of  the  stomach,  &r,  174 

Moulting  of  birds,  176 

Cast  skins  sometimes  devoured,  177 

Mis-statement  of  Goldsmith,  ib. 

Contrivances  for  escape  from  confinement,  178 

Muscular  strength  ofinsects,  179 

Fleas  made  to  draw  miniature  coaches,  180 
Numerous  muscles  of  the  cossus, 

Its  wonderful  strength,  184 

Mis-statements  respecting  the  strength  ofinsects,  185 

Means  of  escape  by  spinning,  186 

Defensive  hairs  and  spines  of  caterpillars,  187 

Excrementitious  covering  of  some  larvae,  190 

Origin  of  the  froth  on  plants  called  cuckoo-spify  191 

Winter  covering  of  caterpillars,  192 

Fat  a  probable  defence  against  cold,  195 

CHAPTER  VIII. 

Voracity  of  caterpillars,  grubs,  and  maggots,  196 

Increase  of  weight  in  the  silk'wonn  in  thirty  days,  197 

Remarkable  change  in  the  capacity  of  the  stomach,  198 

Instances  of  human  voracity,  201 

Jaws  or  mandibles  of  larvsR,  202 

Caterpillars,  ib. 

Blight  caused  by  an  oak-leaf-roller,  203 

Ravages  of  the  buff-tip,  204 

Encamping  caterpillars  of  the  ermine  moths,  205 

Experiments  with  these,  206 

Extraordinary  ravages  of  the  brown-tail  moth,  208 

Strange  enactment  of  the  Parliament  of  Paris,  209 
Cause  of  the  abundance  of  caterpillars  in  particular 

years,  210 

Alarm  caused  in  France  by  the  gamma  moth,  211 

Calculation  of  their  fecundity,  212 

Cabbage  caterpillars  prefer  weeds,  213 

Disappearance  of  the  black-veined  white  butterfly,  214 
Ravages  of  the  caterpillar  of  the  gooseberry  saw-fly,     215 

Similar  ravages  committed  on  other  trees,  216 

Slug  worm  of  North  America,  217 
Turnip  fly  erroneously  fancied  to  come  across  the  sea 

to  Norfolk,  218 

Effects  of  JEgerise  on  currant  and  poplar  trees,  220 

Destruction  of  grain  by  Euplocami  and  Tinse,  221 

Bee-hives  injured  by  Gallarise,  222 

Caterpillar  which  feeds  on  chocolate,  224 

CHAPTER  IX. 

Voracity  of  grubs,  225 

Grub  of  the  cockchafer  or  maj-bug,  226 

Account  of  its  transformation,  &c,  227 


CONTENTS.  Vll 

Page 

Methods  of  destroying, 

Wire  worm  the  grub  of  Hemirhipus, 

Probable  mistake  respecting  the  destruction  of  wheat,    231 

Pea  beetle  of  North  America, 

Corn  weevil,  234 

Meal  worm,  the  grub  of  Tenebrio  molitor,  ib. 

Tabby  moth  caterpillar  devours  butter  and  fat,  236 

Intestinal  worms,  ib. 
Mistakes  of  Linnaeus,  Dr  Barry,  and  Dr  J.  P.  Frank,  237 
Experiment  of  M.  Deslonchamps, 

Extraordinary  case  of  Mary  Riordan,  by  Dr  Pickells,    239 

Authenticity  of  this  case  proved,  241 

Fruit  grubs,  242 

N ut  weevil  and  its  transformations,  ib. 
Apple-bud  weevil,                                                               .    243 

Voracity  of  Calosoma,  244 

Rayed  galleries  of  a  bark-grub,  245 

Ravages  of  locusts,  246 

Their  swarms  in  Southern  Africa,  247 

The  Italian  locust,  249 

Migrations  in  Palestine  and  Europe,  250 

CHAPTER  X. 

Voracity  of  maggots,  252 

Maggots  of  crane  flies  popularly  called  the  grub,  ib. 

Remarkable  ovipositor,  253 

Destruction  of  herbage  on  Blackheath,  254 

Similar  devastations  in  Poitou  and  Holderness,  255 

Wheat  fly,  described  by  Mr  Shireff,  256 

Additional  particulars  by  Mr  Gorrie,  259 

Observations  ofKirby,  260 

Mistake  of  Mr  Markwick,  261 

Hessian  fly,  as  described  by  Mr  Say,  262 

Cheese-hopper  the  maggot  of  Piophila,  263 

Wonderful  structure  of  this  maggot,  264 

Its  transformation  into  a  fly,  265 

Origin  of  the  house  fly  (Musca  domestica),  266 

Mistakes  of  Ray  and  Reaumur,  267 

Voracity  of  the  maggots  of  blow-flies,  268 

Instance  of  man  devoured  by  them,  \\3t 

Popular  mistake  respecting  lady-birds,  ggg 

Thair  transformations  traced  to  the  egg,  270 
Aphides  checked  by  these  and  by  Syrphidae, 

SECTION  III.— PUP^E. 

CHAPTER  XI. 

Mechanism  of  suspending  chrysalides,  272 
Proceedings  of  larvae  upon  their  approaching  change,  273 
In  what  manner  some  caterpillars  suspend  themselves,  274 


Viii  CONTENTS. 

Page 

Their  attempts  sometimes  unsuccessful, 
Organ  for  holding  fast, 

Suspensory  cincture  of  other  caterpillars,  279 

Method  of  forming-  this  by  the  swallow-tail,  "281 
Parchment-like  pupa  case  of  flies  (Muscidce), 

Flask-shaped  pupae  of  Syrphidae,  284 

Transformations  of  a  Tipulidan  gnat,  285 

Mode  by  which  the  nymph  is  suspended,  286 

Hooked  aquatic  pupa  (Hydrocampa?)^  287 

CHAPTER  XII. 

Form  and  structure  of  pupae,  288 

The  term  of  Metamorphosis  objected  to,  ib. 

Harvey's  fancies  about  transmutation,  289 
Similar  fancies  of  Goedart  exposed  by  Swammerdam,    290 

Structure  of  the  pupa  of  the  chameleon  fly,  292 

Pupa  of  the  lappit  moth,  293 
Chrysalis  and  transformations  of  the  peacock  butterfty,  294 

Origin  of  philosophic  errors,  296 

Changes  produced  on  pupae  by  evaporation,  297 

Objections  to  the  theory  of  evaporation,  298 

Respiratory  organs  of  pupa?,  300 

Experiments  upon  the  breathing  of  pupae,  301 

Valves  of  the  spiracles,  302 
Breathing  apparatus  in  the  pupae  of  aquatic  crane  flies 

and  gnats,  304 

Plumed  apparatus  of  the  blood-worm,  305 

CHAPTER  XIII. 

Transformation  of  pupae  into  perfect  insects,  307 

Theory  of  transpiration  by  means  of  heat,  ib. 

Objections  to  this  theory,  308 

Experiments  by  Reaumur,  309 

Chrysalides  hatched  under  a  hen,  310 

Forcing  of  butterflies  in  winter,  311 

Retarding  the  evolution  of  butterflies  by  cold,  312 

Experiments  on  pupae  led  to  the  varnishing  of  eggs,  ib. 

Illustrations  of  torpidity  in  animals  and  plants,  313 

Various  periods  of  disclosure  in  the  same  brood,  314 

Supposed  final  cause  of  this,  315 
Fixed  time  of  the  day  for  some  insects  to  be  evolved,      316 

Remarkable  evolution  of  the  gnat,  317 

Still  more  remarkable  instance  of  the  blood-worm,  319 

Netted  doors  in  the  pupa  cases  of  caddis-flies,  320 

Bellows-apparatus  in  the  pupa  of  the  blow-fly,  321 

Contrivance  in  the  pupae  of  wood  feeders,  322 

Singularity  in  the  locust  moth,  323 

Ingenious  contrivance  in  a  small  leaf  roller,  324 


CONTENTS.  IX 

Page 

Mistake  of  Bonnet  with  respect  to  the  teazle-moth,  325 

Pupa  cases  opened  by  extraneous  assistance,  328 

Observations  on  this  by  the  younger  Huber,  327 

Experiment  by  Dr  J.  R.  Johnson,  329 
De  Geer's  observations  contrary  to  those  of  Svvara- 

merdam,  330 

Remarkable  circumstance  in  the  hive  bee,  331 
SECTION  IV.     PERFECT  INSECTS. 

CHAPTER  XIV. 

Expansion  of  the  body  and  wings  in  insects  newly  trans- 
formed, 333 
Structure  of  birds  to  contain  air,  ib. 
Expansion  in  the  fly  of  the  ant-lion,  334 
The  mandibles  prove  it  carnivorous,  335 
Transformations  of  dragon-flies,  336 
Folded  wings  of  some  two  winged  flies,  338 
Malpighrs  account  of  the  transformations  of  the  silk- 
worm, 339 
Impulsion  of  fluids  into  the  wings,  341 
Kirby's  account  of  the  expansion  of  the  swallow-tailed 

butterfly,  342 

Swammerdam's  account  of  the  wings  of  the  bee,  343 

Air-tubes  in  insects'  wings,  344 

Nervures  in  the  wings  of  plumed  moths,  345 

Perfect  insects  do  not  increase  in  size,  347 

Imperfect  insects  from  fallen  chrysalides,  349 

Discharges  from  newly-evolved   insects,  350 

Supposed  showers  of  blood  accounted  for,  351 

Theories  devised  to  account  for  crimson-snow,  352 

Curious  fact  explaining  this,  by  Mr  T.  Nicholson,  354 

Does  not  explain  the  red  snow  of  the  Alps,  355 

CHAPTER  XV. 

Peculiar  motions  of  insects,  356 

Motion  indispensable  to  life,  ib. 

Anecdote  of  a  water-measurer,  357 

Mode  of  combing  themselves  used  by  spiders,  358 

Oscillatory  motions  of  some  tipulidae,  359 

Vibratory  motions  of  syrphi  on  the  wing,  360 

Similar  motions  of  hawks,  red-breast,  &c,  361 

Experiment  on  Scioptera  vibrans^  362 

Illustrated  by  the  wag-tail,  &c,  363 

Gnat  dances  in  winter,  ib. 

Opinion  of  Wordsworth  and  others,  364 

Similar  aerial  dances  of  rooks,  ib. 

Night-gambols  of  Corethrce  ?  on  a  book,  365 

Circular  movements  of  a  summer  fly,  366 

Sportive  movements  not  necessarily  social,  367 
Account  of  the  whirlwig,  by  Kirby  and  by  Knapp,       ^  36& 
VOL.  VI.                             B* 


X  CONTENTS. 

Page 

Remarkable  structure  of  its  eyes, 

Battles  of  butterflies, 

Choral  assemblies  of  ephemeridae,  273 

Account  of  these  by  Reaumur,  ib. 

Sports  of  ants,  376 

GjTnnastics  of  ants,  according  to  Huber,  377 

CHAPTER  XVI. 
Peculiar  locomotions  of  insects, 

Examples  from  quadrupeds,  ib. 

Singular  movements  of  some  plant-bugs,  380 

Sailing  of  the  whirlwig  beetle, 

Walking  on  water  by  spiders,  &c, 

Walking  through  water  by  aquatic  mites, 

Oblique  pace  of  midges, 

Insect  with  its  legs  on  its  back, 

Rapid  galloping  of  the  strawberry  mite,  386 

Slow  movements  of  the  oil-beetles, 

Supposed  sponges  in  the  foot  of  the  fly,  388 

Correct  notions  of  Derham  and  White,  proved  by  Sir 
E.  Home, 

Apparatus  in  the  feet  of  flies, 

Leaping  muscles  of  the  flea, 

Leaping  of  grasshoppers  and  Springtails, 

Springing  of  spiders  on  their  prey,  394 

Flight  of  insects,  395 

Mechanism  of  insects'  wings  and  their  muscles,  ac- 
cording to  M.  Chabrier,  396 

Flying  of  spiders  without  wings,  397 

CHAPTER  XVII. 

Rest  of  insects,  399 

.Night  insects  rest  in  the  day,  ib. 

Day  movements  of  other  insects,  400 

Insects  have  no  brain  nor  spinal  cord,  ib. 

Want  also  a  proper  heart  as  well  as  blood,  401 

Supposed  pulse  in  insects,  ib. 

No  circulation,  402 
Alleged  discovery  of  an  insect  circulation,  by  Dr 

Carus,  ib. 
How  the  circulation  is  affected  in  the  sleep  of  man,       404 

The  same  effects  cannot  take  place  in  insects,  405 

Sleep  of  senses  not  equally  profound,  406 

Torpidity  of  insects  in  winter,  ib. 

Hybernation  of  ants,  407 

Anecdotes  from  Huber,  408 

Hibernation  of  bees,  410 

Discrepancies  of  opinion  among  naturalists  413 

Hybernation  of  the  hearth  cricket,  414 


ILLUSTRATIONS. 


Page 

1.  Comparative  figures  of  a  bee  and  a  syrphus,  4 

2.  Cell  of  a  queen  of  the  Termites  bellicosi,  broken 

open  in  front;  the  labourers  surrounding  the  queen, 

and  carrying  off  the  eggs,  15 

3.  Groups  of  eggs  of  the  rose-leaf  roller  on  a  pane  of 
glass,  20 

4.  Plants  of  sphcerobulus,  natural  size,  26 

5.  Ditto,  magnified  view,  ib. 

6.  Ditto,  sectional  view,  with  the  seed  just  previous  to 

projection,  ib« 

7.  Ditto,  with  the  seed  in  the  act  of  projection,  ib. 

8.  Ditto,  immediately  after  projection,  ib. 

9.  Microscopic  views  of  applo  and  pear  mould,  30 

10.  Eggs  of  a  butterfly  and  of  a  moth,  magnified,  41 

11.  Magnified  egg  of  the  angle-shades  moth,  42 

12.  Sea  egg,  natural  size,  ib. 

13.  Rgg  of  the  meadow  brown  butterfly,  magnified,  43 

14.  Egg  of  the  brimstone  moth,  magnified,  ib. 

15.  Dung-fly,  with  its  eggs  magnified,  and  mode  of  depo- 
sition, 44 

16.  Lace-winged  fly,  and  position  of  its  eggs  on  a  twig  of 
lilac,  45 

17.  Ichneumon  fly,  with  its  ovipositor,  magnified,  57 

18.  Ichneumon  flies  ovipositing,  58 

19.  Generation  of  ichneumons,  seven  figures,  62 

20.  Magnified  view  of  a  parasite  fly  (Evania  apendi- 

g  aster) ,  66 

21.  Bee  parasite  (Stylops  Melitta},  67 

22.  Leaf-mining  maggots  and  fly,  four  figures,  70 

23.  Gnats  forming  their  egg-boats,  74 


Xli  ILLUSTRATIONS. 

Page 

24.  Magnified  view  of  the  boat  of  gnats'  eggs,  75 

25.  Female  gypsey  moths,  and  modes  of  depositing  their 

eggs,  four  figures,  81 

26.  Females  of  the  brown  and  gold-tailed  moths,  two 

figures,  83 

27.  Tweezers  of  the  brown  and  gold-tailed  moths,  mag- 

nified, two  figures,  84 

28.  Spiral  groups  of  eggs  of  an  unknown  moth,  85 

29.  Eggs  of  the  lackey  moth  wound  spirally  round  a  twig 

of  hawthorn,  natural  size  and  magnified,  two  figures,     86 

30.  Eggs  of  the  coccus,  covered  with  down,  and  with  the 

bodies  of  the  mothers,  89 

31.  Magnified   cochenille  insects,  male  and  female,  two 

figures,  ib. 

32.  Eggs  of  the  hawthorn  coccus,  covered  by  the  body  of 

the  dead  mother,  91 

33.  Ditto,  one  of  these  magnified,  ib. 

34.  Section  of  ditto,  showing  the  eggs  within,  ib. 

35.  Suspended  spiders'  nests,  three  figures,  94 

36.  Vapourer  moth,  male  and  female,  and  deposition  of 
eggs,  three  figures,  95 

37.  Drum  of  the  ear,  showing  that  there  is  no  passage 

through  it  to  the  brain,  103 

38.  Chequered  blow  fly,  1 10 

39.  Abdomen  of  ditto,  opened  and  magnified,  showing 

the  coil  of  young  larvae,  ib. 

40.  Coil  of  larvae  of  ditto,  partly  unwound,  ib. 

41.  Large  gray  blow-fly,  with  the  abdomen  opened,  show- 

ing the  young  maggots,  111 

42.  Breathing  apparatus  of  the  maggot  of  a  large  gray 

blow-fly,  ib. 

43.  Spider  flies,  two  figures >  117 

44.  Generation  of  a  water-mite,  four  figures,  121 

45.  Hatching  of  the  egg  of  the  garden  spider,  four  figures,     1 24 

46.  Egg  of  the  privet  hawk  moth,  magnified,  showing  the 

inclosed  embryo,  125 

47.  Caterpillar  of  ditto,  when  grown,  ib. 

48.  Construction  of  eggs  to  facilitate   the  escape  of  the 

larvas,  three  figures,  126 

49.  Supposed  animal  and  vegetable  metamorphoses,  131 

50.  Egg  of  the  large  cabbage  butterfly,  133 
5  i .  Embryo  butterflies  as  they  appear  in  the  bodies  of  ca- 
terpillars, two  figures,                                                     135 

52.  Female  of  the  perfect  cabbage  butterfly,  ib. 

53.  Magnified  view  of  a  section  of  the  bud  of  a  laburnum,    1 36 


ILLUSTRATIONS.  Xlli 

Page 

54.  Section  of  a  bean-seed,  136 

55.  Seed-leaves,  root,  and  first  true  leaf  of  the  beech,  ib. 

56.  Dissection  of  the  water-grub  of  a  May-fly,  139 

57.  Caterpillars  of  the  Clifden  nonpareil  feeding  on  the 

gray  poplar,  142 

58.  Ditto,  in  a  more  advanced  stage  of  growth,  143 

59.  Walking-leaf  insect  magnified,  144 

60.  Transformations  of  the  brimstone  moth,  145 

61.  Caterpillars  of  the  swallow-tailed  moth,  146 

62.  A  two-winged  fly  (  Volucella  plumat a),  149 

63.  Transformations  of  the  puss  moth,  152 

64.  Lobster  caterpillar,  153 

65.  Aquatic  grubs  of  gnats  in  a  glass  vessel  of  water,  155 

66.  LarvsB  of  the  common-gnat,  floating  in  water,  two 

figures,  156 

67.  Buoy-like  structure  in  the  tail  of  a  water-grub  of  a 

two-winged  fly,  157 

68.  Telescopic-tailed  water-larvae,  three  figures,  158 

69.  Water-worms,  two  figures,  159 

70.  Grub  of  the  dragon-fly,  and  various  parts  of  its  body 

magnified,  five  figures,  162 

71.  Mask  of  the  dragon-fly  grub,  four  figures,  164 

72.  Moulting  of  caterpillars,  and  magnified  views  of  parts, 

ten  figures,  172 

73.  Exuvia  and  pulmonary  vessels  of  the  rhinoceros  beetle,  175 

74.  Goat  moth  caterpillar  escaping  from  a  drinking-glass ,  178 

75.  Magnified  view  of  the  dorsal  muscles  of  the  upper  half 

ofthecossus,  182 

76.  Caterpillar  of  cossus  escaping  from  under  a  loaded 

glass,  184 

77.  Methods  used  by  spiders  and  caterpillars  for  ascending 

their  threads,  186 

78.  Caterpillar  of  the  tiger-moth,  two  figures,  187 

79.  Grub  of  the  museum  beetle,  natural  size  and  magni- 

fied, two  figures,  ib. 

80.  Tail  of  ditto,  magnified,  ib. 

81.  Hairs  of  ditto,  magnified,  two  figures,  ib. 

82.  Thorny  hairs  of  caterpillars,  three  figures,  189 

83.  Green  tortoise  beetle  (Cassida  equestris),  191 

84.  Grub  of  ditto,  magnified,  to  show  its  anal  forks,  ib. 

85.  Grub  of  ditto,  with  its  canopy  of  excrements,  ib. 

86.  Spit  frog-hopper,  and  froth  covering  the  grub  of  the 

same,  two  figures,  192 

87.  Caterpillar  of  the  drinker  moth,  two  figures,  194 

88.  Caterpillar  of  the  angle-shades  moth,  ib. 


XIV  ILLUSTRATIONS. 

89.  Moth  of  ditto,  194 

90.  Viscera  of  the  cossus,  two  figures, 

91.  Caterpillar  of  Vanessa  urtica,  magnified,  200 

92.  Intestines  of  ditto,  ib. 

93.  Intestinal  canals  of  the  caterpillar,  pupae,  and  butter- 
,       fly,  five  figures, 

94.  Buft-tip  caterpillar,  and  moth  of  ditto,  two  figures,  204 

95.  Encampment  of  the  caterpillar  of  the  small  ermine 

on  the  Siberian  crab, 

96.  Transformations  of  the  gamma  moth,  five  figures,  212 

97.  Saw-fly    of  the   gooseberry,   and  caterpillars,   four 

figures,  214 

98.  Caterpillar  of  the  saw-fly  (Nematus  Caprea)   on 

the  osier,  217 

99.  Caterpillar  of  the  saw-fly  (Selandria  alni)  on  the 

alder,  ib. 

100.  Transformations  of  the  grain  moth,  seven  figures,  221 

101.  Transformations   of  the   honeycomb    moth,  seven 

figures,  223 

102.  Transformations  of  the  cockchafer,  nine  figures,  227 

103.  Wire-worm  and  click  beetle,  230 

104.  Zabrus  gibbus,  231 

105.  Melolontha  ruficornis,  ib. 

106.  Corn  weevil,  234 

107.  Meal-worm,  and  the  beetle  produced  from  it,  235 

108.  Transformations  of  the  tabby  moth,  six  figures,  236 

109.  Intestinal  worms,  three  figures,  239 

110.  Churchyard  beetle,  in  the  grub  and   perfect  state, 

four  figures,  241 

111.  Nut  and  apple-tree  beetles,  eight  figures,  243 

112.  Bark  mined  in  rays  by  beetle  grubs,  245 

113.  Locust,  251 

114.  Ovipositor  and  eggs  of  the  crane-fly,  253 

115.  Crane  fly  ovipositing,  and  the  larva  beneath  in  the 

earth  feeding  upon  grass  roots,  254 

116.  Germination  of  a  grain  of  wheat,  259 

117.  Transformation  of  the  wheat-fly,  three  figures,  260 

118.  The  Hessian  fly,  261 

119.  The  Markwick  fly,  ib. 

120.  Transformations  of  the  cheese-hopper,  seven  figures,  265 

121.  Transformations  of  Bibio  hortulanus,  six  figures,  267 

122.  Transformations  of  the  lady-bird,  six  figures,  270 

123.  Transformations  of  the  lace-winged  fly  and  syrphus, 

five  figures,  271 

124.  Caterpillar  of  Vanessa  Jlntiopa,  three  figures,  274 


ILLUSTRATIONS.  XV 

125.  Suspended  caterpillar  of  Vanessa  JLntiopa  splitting 

its   skin   for  the  evolution  of  the  chrysalis,  four 
figures,  276 

126.  Chrysalides  of  Vanessa  urticce  suspended,  with  the 

anal  hooks  magnified,  and  old  skin  fallen  off,  four 
figures,  278 

127.  Black-veined  white  butterfly,  caterpillar,  and  chry- 

salis, three  figures,  280 

128.  Caterpillar  and  chrysalis  of  swallow-tailed  butterfly, 

three  figures,  281 

129.  Pupae  of  blow-fly  and  syrphus,  four  figures,  284 

130.  Transformations  of  the  gnat  (Corethra  plumicor- 

ms),  six  figures,  287 

131.  Pupa  of  chameleon  fly,  three  figures,  292 

132.  Pupa  of  lappit  moth,  three  figures,  294 

133.  Chrysalis  of  Gonepteryx  Rkamni,  300 

134.  Pupa  of  Laria  fascelina,  ib. 

135.  Pupa  of  Sphinx  Ligustri,  ib. 

136.  Spiracles  of  pupae,  two  figures,  302 

137.  Pupae  of  the  gnat  and  Tipula ,  four  figures,         304 

138.  Transformations  of   Chironomus  plumosus,  four 

figures,  305 

139.  Case  fly,  with  the  pupa,  and  the  grate-works  of  the 

opening  of  the  latter,  four  figures,  321 

140.  Pupas  of  Cossus  and  JEgeria,  323 

141.  The  fly  and  pupa  of  the  ant-lion,  four  figures,  335 

142.  Transformation  of  the  dragon-fly,  five  figures,  337 

143.  Blow-fly,  magnified,  two  figures,  338 

144.  Wings  of  insects,  showing  the  nervures,  six  figures,  344 

145.  Twenty-plume  moth,  two  figures,  345 

146.  White-plume  moth,  ib. 

147.  Specimens  of  deformed  butterflies  and  moth,  three 

figures,  350 

148.  Red  spider,  and  the  head,  magnified,  two  figures,  359 

149.  Head  of  the  garden  spider  magnified,  ib. 

150.  Phalangium,  360 

151.  Hydrometra  stagnorum,  magnified,  ib. 

152.  Ploiaria  vagabunda,  magnified,  381 

153.  Neides  elegans,  magnified,  ib. 

154.  Hydrometra  stagnorum,  natural  size,  382 

155.  Hydrachna  geographica,  magnified,  two  figures,  ib. 

156.  Velia  rivulorum,  ib. 

157.  Julus  terrestris,  two  figures,  386 

158.  Oil-beetle,  ib. 


Xvi  ILLUSTRATIONS. 

159.  Nycteribia  Hermanni,  386 

160.  Feet  of  the  fly,  greatly  magnified,  four  figures,  391 

161.  Flea,  magnified,  392 

162.  Velvet  spring-tail,  magnified,  394 

163.  American  spider  (Mygale  avicularia)   destroying 

a  bird,  395 

164.  Muscular  ribbons  for  moving  the  wings  in  Syrphus 

inanis,  magnified,  two  figures,  397 

165.  Syrphus,  398 


INSECT    TRANSFORMATIONS. 


SECTION  I.  — EGGS  OF  INSECTS. 


CHAPTER  I. 

All  Insects  come  frdm  Eggs  as  Plants  do  from  Peeds.  —  Vulgar  errors  of 
Insects  being  generated  by  Putrefaction  and  Blighting  Winds  disproved 
by  experiment. 

IT  was  universally  believed  by  the  ancient  philoso- 
phers, that  n.aggots,  flies,  and  other  insects  were 
generated  from  putrefying  substances.  This  opinion 
continues  to  be  held  by  uninformed  persons  among 
ourselves;  —  though  it  would  be  equally  correct  to 
maintain,  that  a  flight  of  vultures  had  been  generated 
by  the  dead  carcass  which  they  may  be  seen  devour- 
ing, or  a  flock  of  sheep  from  the  grass  field  in  which 
they  graze.  Another  opinion,  perhaps  still  more  gene- 
rally diffused,  is  that  caterpillars,  aphides,  and  other 
garden  insects  which  destroy  the  leaves  of  plants,  are 
generated,  propagated,  or,  at  least,  spread  about,  by 
certain  winds  or  states  of  the  air,  mysteriously  and 
indefinitely  termed  blight.  The  latter  belief  is,  pro- 
bably, not  so  easy  of  immediate  refutation  as  the  for- 
mer;—  but,  as  we  shall  endeavour  to  show,  it  seems 
to  us  to  be  equally  erroneous. 

The  small  size  of  insects  renders  it  somewhat  easy 
to  pass  off  fanciful  opinions  regarding  them,  since  it 
is  difficult  for  common  observers  to  detect  mistakes, 

VOL.  vi.  1 


2  INSECT    TRANSFORMATIONS. 

but  similar  notions  have  been  entertained  by  writers 
of  no  mean  reputation,  respecting  even  the  larger 
animals.  The  celebrated  Kircher,  for  example,  one 
of  the  most  learned  men  of  the  seventeenth  century, 
goes  so  far  as  to  give  the  following  singular  recipe  for 
the  manufacture  of  snakes  :  — 

f  Take  some  snakes,'  says  he,  c  of  whatever  kind 
you  want,  roast  them,  and  cut  them  in  small  pieces, 
and  sow  those  pieces  in  an  oleaginous  soil;  then, 
from  day  to  day,  sprinkle  them  lightly  with  water 
from  a  watering-pot,  taking  care  that  the  piece  of 
ground  be  exposed  to  the  spring  sun,  and  in  eight 
days  you  will  see  the  earth  strewed  with  little  worms, 
which,  being  nourished  with  milk  diluted  with 
water,  will  gradually  increase  in  size  till  they  take 
the  form  of  perfect  serpents.  This,'  he  subjoins 
with  great  simplicity,  £  I  learned  from  having  found 
in  the  country  the  carcase  of  a  serpent  covered  with 
worms,  some  small,  others  larger,  and  others  again 
that  had  evidently  taken  the  form  of  serpents.  It 
was  still  more  marvellous  to  remark,  that  among 
these  little  snakes,  and  mixed  as  it  were  with  them, 
were  certain  flies,  which  I  should  take  to  be  engen- 
dered from  that  substance  which  constituted  the 
aliment  of  the  snakes.'* 

Kircher's  more  shrewd  and  less  fanciful  cor* 
respondent,  Redi,  determined  to  prove  this  singular 
recipe  before  he  trusted  to  the  authority  of  his  friend. 
<  Moved,'  he  says,  c  by  the  authentic  testimony  of 
this  most  learned  writer,  I  have  frequently  tried  the 
experiment,  but  I  could  never  witness  the  genera- 
tion of  those  blessed  snakelets  made  to  hand.|' 
But  though  Redi  could  not,  in  this  way,  produce  a 
brood  of  snakes,  his  experiments  furnished  an 
abundant  progeny  of  maggots, — the  same,  unques- 

*  Athan.  Kircher,  Mund.  Subterran.  lib.  xii. 

t  Redi,  Generat.  Insectorum,  edit,  Amstel.  1686. 


GENERATION    OF    INSECTS.  O 

tionably,  that  the  imagination  of  Kircher  had  magni- 
fied into  young  snakes,  —  which,  being  confined  in 
a  covered  box,  were  in  a  short  time  transformed  into 
flies,  at  first  of  a  dull  ash. colour,  wrinkled,  un- 
finished, and  their  wings  not  yet  unfolded,  —  as  is 
always  the  case  with  winged  insects  just  escaped 
from  their  pupa  case.  In  less  than  an  hour,  how- 
ever, they  '  unfolded  their  wings,  and  changed  into 
a  vivid  green,  marvellously  brilliant '  —  most  proba- 
bly the  green  flesh-fly  (Musca  Ccesar.  LINN.) 

It  is  a  common  opinion  in  this  country,  particu- 
larly in  the  north,  that  if  a  horse's  hair  be  put  into 
the  water  of  a  spring  or  a  ditch,  it  will  be  in  process 
of  time  transformed,  first  into  a  hair-worm,  and  after- 
wards into  an  eel.  The  deception,  as  in  the  instance 
of  Kircher's  snakes,  arises  from  the  close  resemblance 
between  a  hair  and  the  hair-worm  ( Gordius  aquati- 
cus,  LINN.),  and  between  this  and  a  young  eel.  This 
fabled  transformation  of  hair,  which  we  have  heard 
maintained  even  by  several  persons  of  good  educa- 
tion, is  physically  impossible  and  absurd. 

The  method  laid  down  by  Virgil  in  his  Georgics 
for  generating  a  swarm  of  bees  is  precisely  of  the 
same  description  as  the  snake  recipe  of  Kircher;  and 
though  the  c  Episode  of  Aristseus  recovering  his  bees ' 
has  been  pronounced  to  be  '  perhaps  the  finest  piece 
of  poetry  in  the  world,'  we  must  be  permitted  to  say 
that  it  is  quite  fabulous  and  unphilosophical.  The 
passage  runs  thus : — 

Oft  from  putrid  gore  of  cattle  slain 
Bees  have  been  bred.     *  *  *     A  narrow  place, 
And  for  that  use  contracted,  first  they  choose. 
Then  more  contract  it,  in  a  narrower  room, 
Wall'd  round,  and  cover'd  with  a  low  built  roof, 
And  add  four  windows,  of  a  slanting  light 
From  the  four  winds.     A  bullock  then  is  sought4 
His  horns  just  bending  in  their  second  year; 


4  INSECT    TRANSFORMATIONS. 

Him,  much  reluctant,  with  o'erpow'ring  force, 
They  bind;  his  mouth  and  nostrils  stop,  and  all 
The  avenues  of  respiration  close; 
And  buffet  him  to  death:   his  hide  no  wound 
Receives;  his  battered  entrails  burst  within. 
Thus  spent  they  leave  him;  and  beneath  his  sides 
Lay  shreds  of  boughs,  fresh  lavender  and  thyme. 
This,  when  soft  zephyr's  breeze  first  curls  the  wave, 
And  prattling  swallows  hang  their  nests  on  high. 
Meanwhile  the  juices  in  the  tender  bones 
Heated  ferment;  and,  wondrous  to  behold, 
Small  animals,  in  clusters,  thick  are  seen, 
Short  of  their  legs  at  first:  on  filmy  wings, 
Humming,  at  length  they  rise;  and  more  and  more 
Fan  the  thin  air;   'till,  numberless  as  drops 
Pour'd  down  in  rain  from  summer  clouds,  they  fly.' 

TRAPP'S  VIRGIL,  Georg.  iv,  369. 

Columella,  a  Roman  writer  on  rural  affairs,  after 
directing  in  what  manner  honey  is  to  be  taken  from 
a  hive  by  killing  the  bees,  says,  that  if  the  dead  bees 
be  kept  till  spring,  and  then  exposed  to  the  sun  among 
the  ashes  of  the  tig-tree,  properly  pulverised,  they  may 
be  restored  to  life. 

These  fancies  have  evidently  originated  from  mis- 
taking certain  species  of  flies  (Syrphi,  Bombylii, 
&c,)  for  bees,  which,  indeed,  they  much  resemble  in 
general  appearance  ;  though  they  have  only  two 
wings,  and  short  antenna?,  while  all  bees  have  four 
wings,  and  long  antennae.  Neither  the  flies  nor  the 


b 

Comparative  figures  of  a  bee  (a)  and  a  syrplms  (b). 

bees  are  produced  by  putrefaction; — but  as  the  flies 
are  found  about  animal  bodies  in  a  state  of  decom- 
position, the  ancients  fell  into  an  error  which  accurate 
observation  alone  could  explode.  The  maggots  of 


GENERATION    OF    INSECTS.  5 

blow-flies,  as  Swammerdam  remarks,  so  often  found 
in  the  carcasses  of  animals  in  summer,  *  somewhat 
resemble  those  produced  by  the  eggs  of  bees.  How- 
ever ridiculous,'  he  adds,  c  the  opinion  must  appear, 
many  great  men  have  not  been  ashamed  to  adopt  and 
defend  it.  The  industrious  Goedart  has  ventured  to 
ascribe  the  origin  of  bees  to  certain  dunghill  worms,* 
and  the  learned  De  Mei  joins  with  him  in  this  opi- 
nion; though  neither  of  them  had  any  observation  to 
ground  their  belief  upon,  but  that  of  the  external  re- 
semblance between  bees  and  certain  kinds  of  flies 
(Syrphidce)  produced  from  those  worms.  The  mis- 
take of  such  authors  should  teach  us,'  he  continues, 
*  to  use  great  caution  in  our  determinations  concern- 
ing things  which  we  have  not  thoroughly  examined, 
or  at  least  to  describe  them  with  all  the  circum- 
stances observable  in  them.  Therefore,  although 
this  opinion  of  bees  issuing  from  the  carcasses  of 
some  other  animals  by  the  power  of  putrefaction, 
or  by  a  transposition  of  parts,  be  altogether  absurd, 
it  has  had,  notwithstanding,  many  followers,  who 
must  have  in  a  manner  shut  their  eyes  in  order  to 
embrace  it.  But  whoever  will  attentively  consider 
how  many  requisites  there  are  for  the  due  hatching 
of  the  bee's  egg,  and  for  its  subsistence  in  the  grub 
state,  cannot  be  at  a  loss  for  a  clue  to  deliver  him- 
self out  of  that  labyrinth  of  idle  fancies  and  unsup- 
ported fables,  which,  entangled  with  one  another  like 
a  Gordian  knot,  have  even  to  this  day  obscured  the 
beautiful  simplicity  of  this  part  of  natural  history. 'f 

Redi  was  by  no  means  satisfied  with  the  first  re- 
sults of  his  experiments  upon  the  flesh  of  snakes,  for 

*  The  maggots  of  Eristalis  tenax,  FABR.  E.  apiformis, 
MEIGEN,  and  other  Syrphida,  well  known  in  common  sew- 
ers by  their  long  tails,  like  those  of  rats. 

t  Swammerd.  Book  of  Nature,  i,  228. 

VOL.   VI.  1* 


6  INSECT    TRANSFORMATIONS. 

several  species  of  flies  were  produced,  giving  some 
countenance  to  the  opinion  of  Aristotle,  Pliny,  Mouf- 
fet,  and  others,  that  different  flesh  engenders  different 
flies,  inheriting  the  disposition  of  the  animal  they  are 
bred  from.  He  accordingly  tried  almost  every 
species  of  flesh,  fish,  and  fowl,  both  raw  and  cooked, 
and  soon  discovered  (as  he  could  not  fail  to  do)  that 
the  same  maggots  and  flies  were  produced  indis- 
criminately in  all.  This  ultimately  led  him  to 
ascertain  that  no  maggots  are  ever  generated  except 
from  eggs  laid  by  the  parent  flies:  for  when  he 
carefully  covered  up  pieces  of  meat  with  silk  or 
paper  sealed  down  with  wax,  no  maggots  were 
seen;  but  the  parent  flies,  attracted  by  the  smell  of 
the  covered  meat,  not  unfrequently  laid  their  eggs 
on  the  outside  of  the  paper  or  silk,  the  maggots 
hatched  from  these  dying,  of  course?  for  want  of 
nourishment. 

With  respect  to  bees,  it  becomes  even  more  absurd 
to  refer  their  generation  to  putrefaction,  when  we 
consider  that  they  uniformly  manifest  a  peculiar 
antipathy  to  dead  carcasses.  This  was  remarked  so 
long  ago  as  the  time  of  Aristotle  and  of  Pliny  ;* 
and  Varro  asserts  that  bees  never  alight  upon  an 
unclean  place,  nor  upon  any  thing  which  emits  an 
unpleasant  smell.  This  is  strikingly  exemplified  in 
their  carrying  out  of  the  hive  the  bodies  of  their 
companions  who  chance  to  die  there;  and  in  their 
covering  over  with  propolis  the  bodies  of  snails, 
mice, I  and  other  small  animals  which  they  cannot  re- 
move. J 

These  facts,  which  are  unquestionable,  may  at 
first  view  appear  to  contradict  the  Scripture  history 

*  Aristotle,  Hist.  Animal,  ix,  40.     Pliny  says,  '  Ornnes  car- 
ne  vescuntur,  contra  quarn  apes,  quae  nullum  corpus  aitingunt* 
t  Huish  on  Bees,  p.  100. 
i  Insect  Architecture,  p.  109. 


GENERATION    OF    INSECTS.  7 

of  Sarnson,  who,  having  killed  a  young  lion  in  the 
vineyards  of  Timnath,  *  after  a  time  turned  aside  to 
see  the  carcass  of  the  lion:  and  behold  a  swarm  of 
bees  and  honey  in  the  carcass.'*  It  only  requires 
us,  however,  to  examine  the  facts,  to  show  that 
this  does  not  disagree  with  the  preceding  statement. 
Bochart,  in  his  Sacred  Zoology,  tells  us  that  the 
word  rendered  '  carcass'  literally  signifies  skeleton; 
and  the  Syriac  version  stilt  more  strongly  renders 
it  a  dried  body  (corpus  exsiccatum).  Bochart  fur- 
ther contends,  that  the  phrase  '  after  a  time'  is  one 
of  the  commonest  Hebraisms  for  a  year.  But  when 
we  consider  the  rapid  desiccation  caused  by  the  sum- 
mer suns  of  Palestine,  this  extension  of  time  will  be 
unnecessary;  for  travellers  tell  us  that  the  bodies  of 
dead  camels  become  quite  parched  there  in  a  few 
days.  We  have  the  testimony  of  Herodotus,  that  a 
swarm  of  bees  built  their  cells  and  made  honey  in 
the  dried  carcass  of  a  man  placed  above  the  gate  of 
Athamanta.  Soranus  also  tells  us  of  a  swarm  of 
bees  found  in  the  tomb  of  the  celebrated  Hippocrates. 
'  I  have  been  told,'  says  Redi,  <  by  Albergotto,  a 
man  of  profound  erudition,  that  he  had  seen  a  swarm 
in  the  cranium  of  a  horse.  Bees,'  he  adds,  c  not 
only  do  not  live  upon  dead  bodies,  but  they  will  not 
even  come  near  them,  as  I  have  often  proved  by  ex- 
periment.' '  It  is  probable,'  says  Swammerdam, 
£  that  the  not  rightly  understanding  Samson's  ad- 
venture of  the  lion  gave  rise  to  the  popular  opinion 
of  bees  springing  from  dead  lions,  oxen,  and  horses.' 
Kirby  and  Spense  seem  disposed  to  consider  Sam- 
son's bees,  as  we  have  done  those  of  Virgil,  to  be 
flies  resembling  bees;  but  the  '  honey'  which  Samson 
<  took  in  his  hands  and  went  on  eating,'  is  fatal  to 
such  an  exposition. 

The    ancients    had.  another  fancy    respecting   the 

*  Judges,  xiv,  8. 


8  INSECT    TRANSFORMATIONS. 

propagation  of  bees,  equally  absurd,  though  much 
more  poetical.  Virgil  tells  us  that, 

From  herbs  and  fragrant  flowers,  with  their  mouths 
They  cull  their  young.  Georg.  iv. 

Aristotle*  had  long  before  stated,  and  De  Monfort 
in  modern  times  repeated  the  assertion,!  that  the 
olive,  the  cerinthus,  and  some  other  plants,  have  the 
property  of  generating  young  bees  from  their  purest 
juices.  We  may  well  say,  with  Lactantius,  that 
'  they  make  shipwreck  of  their  wisdom,  who  adopt 
without  judgment  the  opinions  of  their  ancestors, 
and  allow  themselves  to  be  led  by  others  like  a  flock 
of  sheep. 'J  Modern  naturalists,  being  accustomed 
to  minute  accuracy  in  their  observations,  can  both 
disprove  and  readily  explain  most  of  those  erroneous 
fancies,  by  tracing  the  causes  which  led,  and  may  still 
lead,  inaccurate  observers  into  such  mistakes. 

It  would  have  been  well  if  such  unfounded  fancies 
had  rested  here;  but  philosophical  theorists,  both  of 
ancient  and  modern  times,  have  promulgated  dreams 
much  more  extravagant.  The  ancients  taught  that 
the  newly-formed  earth  (hatched  as  some  said  from 
an  egg)  clothed  itself  with  a  green  down  like  that 
on  young  birds,  and  soon  after  men  began  to  sprout 
up  from  the  ground  as  we  now  see  mushrooms  do. 
The  refined  Athenians  were  so  firmly  convinced  of 
their  having  originally  sprung  up  in  this  manner, 
that  they  called  themselves  4  Earth-born'  (Erich- 
thonii),  and  wore  golden  tree-hoppers  (Cicadai)  in 
their  hair,  erroneously  supposing  these  insects  to 
have  a  common  origin  with  themselves.  §  Lucretius 

*  Hist.  Animal,  v,  22. 

t  Le  Portrait  de  la  Mouche  a  Miel.  Liege,  1646. 

t  Divin.  Instit.  ii,  7;  in  Redi's  motto.  Shepherds  on  the 
continent  lead  their  sheep,  as  those  of  Israel  did.  See  Mena- 
geries, vol.  i,  p.  81. 

§  The  Cicadae  do  not  deposit  their  eggs  in  the  earth,  but  on 
trees,  &c.  See  Insect  Architecture,  chap.  vii. 


GENERATION    OF    INSECTS.  9 

affirms,  that  even  in  his  time,  when  the  earth  was  sup- 
posed to  be  growing  too  old  to  be  reproductive,  c  many 
animals  were  concreted  out  of  mud  by  showers  and 
sunshine.'* 

But  the  ancients,  it  would  appear,  had  the  shrewd- 
ness seldom  to  venture  upon  illustrations  of  their  phi- 
losophical romances  by  particular  examples.  This  was 
reserved  for  the  more  reckless  theory-builders  of  our 
own  times.  We  find  Robinet,  for  example,  asserting 
that,  as  it  was  nature's  chief  object  to  make  man,  she 
began  her  *  apprentissage,'  as  he  calls  it,  by  forming 
minerals  resembling  the  single  organs  of  the  human 
body,  such  as  the  brain  in  the  fossil  called  Brain-stone 
(Meandrina  certbriformis,  PARKINSON.)!  Darwin, 
again,  taking  the  hint  from  Epicurus,  dreams  that  an- 
imals arose  from  a  single  filament  or  threadlet  of  mat- 
ter, which,  by  its  efforts  to  procure  nourishment, 
lengthened  out  parts  of  its  body  into  arms  and  other 
members.  For  example,  after  this  filament  had  im- 
proved itself  into  an  oyster,  and  been  by  chance  left 
dry  by  the  ebbing  of  the  tide,  its  efforts  to  reach  the 
water  again  expanded  the  parts  nearest  to  the  sea  in- 
to arms  and  legs.  If  it  tried  to  rise  from  its  native 
rocks,  the  efforts  produced  wings,  and  it  became  an 
insect,  which  in  due  course  of  time  improved  itself 
by  fresh  efforts  till  it  became  a  bird,  the  more  perfect 
members  being  always  hereditarily  transmitted  to  the 
progeny.  The  different  forms  of  the  bills  of  birds, 
whether  hooked,  broad,  or  long,  were,  he  says,  gradu- 
ally acquired  by  the  perpetual  endeavours  of  the  crea- 
tures to  supply  their  wants.  The  long-legged  water- 

*  Multaque  nunc  etiam  existunt  animalia  terris, 
Imbribus  et  calido  soils  concreta  vapore. 

JDe  Nat.  Rer.  v,  795. 

t  Robinet,  Consid.  Philosophiques  dela  Gradation  Naturelle 
<Jes  Formes  de  1'Etre.    Paris,  1768. 


10  INSECT    TRANSFORMATIONS. 

fowl  (Grallatores,  VIGORS)  in  this  way  acquired 
length  of  legs  sufficient  to  elevate  their  bodies  above 
the  water  in  which  they  waded.  c  A  proboscis,'  he 
says,  e  of  admirable  structure  has  thus  been  acquired 
by  the  bee,  the  moth,  and  the  humming-bird,  for  the 
purpose  of  plundering  the  nectaries  of  flowers.'*  La- 
marck, an  eminent  French  naturalist,  recently  deceas- 
ed, adopted  the  same  visions;  and,  among  other  illus- 
trations of  a  similar  cast,  he  tells  us  that  the  giraffe 
acquired  its  long  neck  by  its  efforts  to  browse  on  the 
high  branches  of  trees,  which,  after  the  lapse  of  a  few 
thousand  years,  it  successfully  accomplished. 

Theories  like  the  preceding  all  originate  in  the  en- 
deavours of  human  ingenuity  to  trace  the  operations 
of  nature  farther  than  ascertained  facts  will  warrant  ; 
and  the  necessary  blanks  in  such  a  system,  which 
presupposes  much  that  cannot  be  explained,  are  filled 
up  by  the  imagination.  This  inability  to  trace  the 
origin  of  minute  plants  and  insects  led  to  the  doctrine 
of  what  is  called  spontaneous  or  equivocal  generation, 
of  which  the  fancies  above-mentioned  are  some  of  the 
prominent  branches.  The  experiments  of  Redi  on 
the  hatching  of  insects  from  eggs,  which  were  pub- 
lished at  Florence  in  1668,  first  brought  discredit  up- 
on this  doctrine,  though  it  had  always  a  few  eminent 
disciples.  At  present  it  is  maintained  by  a  consider- 
able number  of  distinguished  naturalists,  such  as 
Blumenbach,  Cuvier,  Bory  de  St  Vincent,  R. 
Brown,  &c.  c  The  notion  of  spontaneous  genera- 
tion,' says  Bory,  £  is  at  first  revolting  to  a  rational 
mind,  but  it  is,  notwithstanding,  demonstrable  by  the 
microscope.  The  fact  is  averred:  Miiller  has  seen 
it,  I  have  seen  it,  and  twenty  other  observers  have 
seen  it  :  the  Pandorinia  exhibit  it  every  instant. 'f 

*  Darwin's  Zoonomia,  sect,  xxxix,  3d  edit.    London,  1801. 
t  Diet.  Classique  d'Hist.  Nat.,  Art.  Microscopiques,  p,  541. 


GENERATION    OF    INSECTS.  1  1 

These  pandorinia  he  elsewhere  describes  as  probably 
nothing  more  than  '  animated  scions  of  Zoocarpae' 
(propagules  animes  des  Zoocarpes.)*  It  would  be 
unprofitable  to  go  into  any  lengthened  discussion  upon 
this  mysterious  subject  ;  and  we  have"  great  doubts 
whether  the  ocular  demonstration  by  the  microscope 
would  succeed  except  in  the  hands  of  a  disciple  of  the 
school.  Even  with  naturalists,  whose  business  it  is  to 
deal  with  facts,  the  reason  is  often  wonderfully  influ- 
enced by  the  imagination. 

But  the  question  immediately  before  us  happily  does 
not  involve  these  recondite  discussions  ;  for  if  even 
pandorinia  and  other  animalcules  were  proved  beyond 
a  doubt  to  originate  in  the  play  of  chemical  affinities 
or  galvanic  actions  —  (a  more  refined  process,  it  must 
be  confessed,  than  Kircher's  chopped  snakes),  it  would 
not  affect  our  doctrine  that  all  insects  are  hatched  from 
eggs  :  for  no  naturalist  of  the  present  day  classes 
such  animalcules  among  insects.  Leaving  animal- 
cules and  zoophytes,  therefore,  out  of  the  question, 
we  have  only  to  examine  such  branches  of  the  theory 
of  spontaneous  generation  as  seem  to  involve  the  pro- 
pagation of  genuine  insects,  —  like  the  fancies  about 
putrefaction  which  we  have  seen  refuted. 

The  notion  that  small  insects,  such  as  aphides 
and  the  leaf-rolling  caterpillars,  are  spread  about,  or 
rather  generated,  by  what  is  termed  blight  (possibly 
from  the  Belgic  blinkan,  to  strike  with  lightning),  is 
almost  universally  believed  even  by  the  most  intel- 
ligent, if  they  have  not  particularly  studied  the  hab- 
its of  insects.  Mr  Main,  of  Chelsea,  an  ingenious 
and  well-informed  gardener  and  naturalist,  describes 
this  as  an  '  easterly  wind,  attended  by  a  blue  mist. 
The  latter  is  called  a  blight,  and  many  people 
imagine  that  the  aphides  are  waited  through  the 

*  Diet.  Class.,  Art.  Pandoriir'es. 


12  INSECT    TRANSFORMATIONS. 

air  by  this  same  mist.'*  c  The  farmer,'  says  Keith, 
1  supposes  these  insects  are  wafted  to  him  on  the 
east  wind,  while  they  are  only  generated  in  the  ex- 
travasated  juices  as  forming  a  proper  nidus  for  their 
eggs. 'I  A  more  detailed  account,  however,  is  given 
by  the  late  Dr  Mason  Good,  and  as  he  speaks  in 
part  from  personal  observation,  and  was  not  only 
one  of  the  most  learned  men  of  his  time,  but  an  ex- 
cellent general  naturalist,  his  testimony  merits  every 
attention :  — 

*  That  the  atmosphere,'  says  Dr  Good,  ( is  freight- 
ed with  myriads  of  insect  eggs  that  elude  our  senses, 
and  that  such  eggs,  when  they  meet  with  a  proper  bed, 
are  hatched  in  a  few  hours  into  a  perfect  form,  is  clear 
to  any  one  who  has  attended  to  the  rapid  and  wonder- 
ful effects  of  what,  in  common  language,  is  called  a 
blight  upon  plantations  and  gardens.  1  have  seen,  as 
probably  many  who  read  this  work  have  also,  a  hop- 
ground  completely  overrun  and  desolated  by  the  aphis 
humuli,  or  hop  green-louse,  within  twelve  hours  after 
a  honey-dew  (which  is  a  peculiar  haze  or  mist  loaded 
with  poisonous  miasm)  has  slowly  swept  through  the 
plantation,  and  stimulated  the  leaves  of  the  hop  to  the 
morbid  secretion  of  a  saccharine  and  viscid  juice, 
which,  while  it  destroys  the  young  shoots  by  exhaus- 
tion, renders  them  a  favourite  resort  for  this  insect, 
and  a  cherishing  nidus  for  myriads  of  little  dots  that 
are  its  eggs.  The  latter  are  hatched  within  eight  and 
forty  hours  after  their  deposit,  and  succeeded  by  hosts 
of  other  eggs  of  the  same  kind;  or,  if  the  blight  take 
place  in  an  early  part  of  the  autumn,  by  hosts  of  the 
young  insects  produced  viviparously;  for,  in  different 
seasons  of  the  year,  the  aphis  breeds  both  ways. 
Now  it  is  highly  probable  that  there  are  minute 

•*  Loudon's  Mag.  of  Nat.  Hist,  i,  180. 
f  Keith's  Physiological  Botany,  ii,  486. 


GENERATION    OF    INSECTS.    '  13 

eggs  or  ovula,  of  innumerable  kinds  of  animalcules 
floating  by  myriads  of  myriads  through  the  atmo- 
sphere, so  diminutive  as  to  bear  no  larger  proportion 
to  the  eggs  of  the  aphis  than  these  bear  to  those  of 
the  wren  or  the  hedge-sparrow;  protected  at  the 
same  time  from  destruction,  by  the  filmy  integument 
that  surrounds  them,  till  they  can  meet  with  a  proper 
nest  for  their  reception,  and  a  proper  stimulating- 
power  to  quicken  them  into  life;  and  which,  with 
respect  to  many  of  them,  are  only  found  obvious  to  the 
senses  in  different  descriptions  of  animal  fluids.'* 

It  appears  to  us  that  it  can  be  nothing  more  than 
a  fancy,  which  is  quite  unsupported  by  evidence,  to 
say  that  the  ejjfr  of  any  species  of  animalcules  or 
insects  float  about  in  the  atmosphere;  for,  independent 
of  their  weight,  (every  known  species  being  greatly 
heavier  than  air,)  the  parent  insects  of  every  species 
whose  history  has  been  accurately  investigated  mani- 
fest the  utmost  anxiety  to  deposit  their  eggs  upon  or 
near  the  appropriate  food  of  the  young.  To  commit 
them  to  the  winds  would  be  a  complete  dereliction  of 
this  invariable  law  of  insect  economy,  But  admit- 
ting for  a  moment  this  hypothesis  that  the  eggs  of 
insects  are  diffused  through  the  atmosphere,  the  cir- 
cumstance must  be  accompanied  with  two  conditions, 
—  the  eggs  must  either  be  dropped  by  the  parents 
while  on  the  wing,  or  be  carried  off  by  winds  from  the 
terrestrial  substances  upon  which  they  may  have  been 
deposited. 

On  the  supposition  that  the  eggs  are  dropped  by  the 
mother  insects  while  on  the  wing,  we  must  also  admit 
(for  there  is  no  avoiding  it)  that  they  continue  to 
float  about,  unhatched,  from  the  end  of  the  summer 
till  the  commencement  of  spring,  at  which  time  only 
the  broods  make  their  appearance.  Yet  when  we 

*  Good's  Study  of  Medicine,  v.  i,  p.  339,  3rd  edition,  Lon- 
don, 1829. 

VOL.    VI.  2 


14  INSECT    TRANSFORMATIONS. 

consider  the  rains,  snows,  and  winds,  to  which  they 
must  be  exposed  for  six  or  nine  months,  we  think 
the  hardest  theorist  would  scarcely  maintain  that  a  sin- 
gle egg  could  out -weather  these  vicissitudes,  and  con- 
tinue to  float  in  the  air.  It  may  not  be  out  of  place 
to  remark,  that  the  female  aphides,  which  deposit  eggs 
in  autumn,  have  no  wings. 

Again,  on  the  supposition  that  the  eggs  are  de- 
posited on  plants,  trees,  or  other  objects,  it  is  still 
more  unlikely  that  they  could  be  carried  into  the  air; 
for,  on  exclusion,  they  are,  with  very  few  exceptions,* 
enveloped  in  an  adhesive  cement  which  glues  them 
to  the  spot  on  which  they  are  deposited.  When 
eggs  are  deposited  singly,  this  cenjj^;  usually  enve- 
lopes each  with  a  thin  coating,  as  in  the  instance  of 
the  admirable  butterfly  (Vanessa  Jltalanta);  but 
when  they  are  placed  in  a  group  the  cement  is  some- 
times spread  over  the  whole,  as  in  the  instance  of  the 
white  satin  moth  (Leucoma  salicis,  STEPHENS), 
This  cement  is  evidently  intended  by  Nature  (who 
seldom  accommodates  her  plans  to  our  theories)  to 
prevent  the  eggs  from  being  carried  from  the  place  se- 
lected by  the  mother  insect  for  their  deposition.  Those 
eggs,  therefore,  which  are  placed  on  the  outside  of 
substances,  have  this  provision  for  their  secure  attach- 
ment to  the  locality  chosen  by  the  instinct  of  the  mother. 
But,  on  the  contrary,  the  principle  does  not  always 
hold  in  the  case  of  those  deposited  in  nests  and  exca- 
vations, and  particularly  as  to  those  of  ants  arid  ter* 
mites.  The  working  ants,  indeed,  carry  the  eggs  from 
the  top  to  the  bottom  of  their  galleries,  according  as 
the  weather  is  favourable  or  unfavourable  for  hatching. 
The  labourers  of  the  white  ants  (Termites),  again,  at- 
tend their  queen  with  the  utmost  care  when  she  is  lay- 
ing; for  as  she  cannot  then  move  about,  they  are  under 
the  necessity  of  carrying  off  the  eggs,  as  they  are  Iaid3 

*  Latreille,  Hist.  Gener,  xiv,  p.  342. 


GENERATION    OF    INSECTS.  15 

to  the  nurseries.  The  extraordinary  labour  which  this 
requires  in  the  community  may  be  understood,  when, 
according  to  Smeathman,  she  lays  60  eggs  in  a  minute, 
which  will  amount  to  86,400  in  a  day,  and  31,536,000 
in  a  year.  The  exceptions  now  mentioned,  howev- 
er, do  not  in  the  least  invalidate  our  general  posi- 
tion. 


Cell  of  a  queen  of  the  Termites  bellicosi,  broken  open  in  front  ;  the 
labourers  surrounding  the  queen  and  carrying  off  her  eggs. 

Another  no  less  remarkable  circumstance  is  the 
great  weight,  or  specific  gravity,  of  the  eggs  of  in- 
sects. From  numerous  experiments  we  may  venture 
to  say  that  those  of  all  the  species  which  we  have 
tried  sink  rapidly  in  water  the  moment  they  are 
thrown  into  it,  from  the  egg  of  the  drinker  moth  (Odo- 
nestis  Potatoria,  GERMAR),  which  is  nearly  as  large 
as  a  hemp-seed,  to  that  of  the  rose-plant  louse  (Aphis 
rosce\  which  is  so  small  as  to  be  barely  visible  to  the 
naked  eye.  Some  eggs  of  the  gipsey  moth  (Hypo- 
gymna  dispar,  STEPHENS),  indeed,  floated  in  water, 
because  they  were  covered  with  down.  It  is  well 
known,  as  we  shall  presently  show,  that  the  diffu- 
sion of  many  of  the  seeds  of  plants  is  accomplished 
by  the  winged  down  with  which  they  are  clothed; 


16  INSECT    TRANSFORMATIONS. 

but  the  down  upon  the  eggs  of  insects  does  not  con- 
duce to  this  end.  Whether  insect  eggs  be  naked  or 
clothed  with  down,  they  are  invariably,  as  far  as  their 
history  has  been  investigated,  deposited  close  to  or 
upon  substances  capable  of  affording  food  to  the  young 
when  hatched.  In  making  experiments  upon  the  spe- 
cific gravity  of  eggs,  it  should  be  remembered  that 
no  infertile  or  unimpregnated  egg  will  sink;  for  having 
some  hundreds  of  these  laid  by  different  species  of 
insects  reared  in  our  cabinet,  we  found,  upon  trial, 
that  they  uniformly  floated,  while  those  which  we  knew 
to  be  impregnated  as  uniformly  sunk.  A  female,  for 
example,  of  the  rose-leaf  roller  (Lozolcenia  Rosana, 
STEPHENS)  was  reared  by  us,  in  solitude,  under  an 
inverted  wine-glass,  upon  the  side  of  which  she  glued 
a  patch  of  eggs,  of  course,  unimpregnated:  these, 
upon  trial,  all  floated  in  water.  But  eggs  of  the  same 
species  taken  from  the  outside  of  a  pane  of  glass 
close  to  a  rose-tree,  all  sunk  in  water;  and  it  is  to  be 
fairly  presumed,  as  the  parent  of  the  latter  was  in  a 
state  of  freedom,  that  these  were  impregnated.  We 
found  the  same  distinction,  indeed,  to  hold  in  the  eggs 
of  the  drinker  moth,  the  gypsey  moth,  and  numerous 
other  insects. *• 

Dr  Good's  account  of  (  honey-dew,'  which  he  des- 
cribes as  c  a  peculiar  haze  or  mist  loaded  with  a  poi- 
sonous miasm,'  that  stimulates  <  the  leaves  of  the  hop 
to  the  morbid  secretion  of  a  saccharine  and  viscid 
juice'  —  appears  to  us  unsupported  by  facts.  Lin- 
naeus,f  on  the  contrary,  who  was  not  wedded  to  the 
meteorological  theory  of  a  miasmatous  haze,  ascribes 
the  honey-dew  on  the  hop  leaves  to  the  caterpillar  of 
the  ghost  moth  (Hepialus  humuli)  attacking  the  roots. 
Dr  Withering,  favouring  this  account,  recommends 
covering  the  roots  with  stones  as  a  preventive;  for 

*  J.  R.  t  Quoted  by  Keith,  Phys.  Bot.   ii,  143. 


GENERATION    OF    INSECTS.  17 

the  caterpillars,  he  avers,  never  attack  wild  hops 
which  grow  in  stony  places,  because  they  cannot 
get  at  the  roots.*  It  appears  to  us,  however,  that 
there  can  be  little  doubt  that  the  sweet  syrupy 
coating,  called  honey-dew3  found  on  the  leaves  of 
the  hop,  is  nothing  more  than  the  excrement  of 
the  insect  (Jlphis  humuli)  whose  propagation  we 
are  discussing.  '  The  honey-dew,'  says  Loudon, 
'  mostly'  (we  believe  always)  c  occurs  after  the  crops 
have  been  attacked  by  these  insects.'!  Sir  J.  E. 
Smith,  who  admits  this  to  be  the  common  cause  of 
honey-dew,  contends  that  what  is  found  on  the  leaves 
of  the  beech  is  an  exception;  but  he  adduces  no  evi- 
dence at  all  satisfactory  in  proof  of  its  being  caused 
by  unfavourable  winds ;|  while  the  undoubted  fact  of 
its  being  the  excrement  of  aphides  in  so  many  other 
instances^  weighs  strongly  against  him. 

A  novel  theory  of  honey-dew  has  just  been  pub- 
lished by  Mr  John  Murray,  who  ascribes  it  to  an 
electric  change  in  the  air.  '  Last  summer,'  he  says, 
£  we  investigated  the  phenomenon  with  great  care: 
the  weather  had  been  parched  and  sultry  for  some 
weeks  previous,  and  the  honey-dew  prevailed  to  such 
an  extent,  that  the  leaves  of  the  currant,  raspberry, 
&c,  in  the  gardens,  literally  distilled  from  their  tips 
a  clear  limpid  honey -dew,  excreted  from  the  plant; 
for  the  phenomenon  was  observable  on  those  plants 
that  were  entirely  free  from  aphides,  and  so  copious 
was  it,  where  these  insects  were  found,  that  had 
their  numbers  been  centuple  they  could  not  cer- 
tainly have  been  the  source  of  the  supply.  The 
question  with  me,  however,  was  set  at  rest  by  ap- 
plying a  lens,  having  previously  washed  and  dried 

*  Botan.  Arrangement,  ii,  440,  3d  ed. 
t  Encycl.  of  Agriculture,  p.  865,  s.  5444. 
t  Introduction  to  Botany,  p.  189, 

§  See  Linn.  Trans,  vol.  vi,  and  Willdenow,  Princ.  of  Bota- 
ny, p.  343. 

VOL.    vi.  2* 


18  INSECT    TRANSFORMATIONS. 

the  leaf  by  a  sponge,  for  in  this  case  the  immediately 
excreted  globules  became  apparent.3* 

In  all  observations  upon  insects,  and  the  other 
minute  parts  of  creation,  it  is  often  exceedingly  dif- 
ficult to  distinguish  between  a  cause  and  an  effect. 
The  question  of  the  formation  of  honey-dew  appears 
to  us  particularly  liable  to  erroneous  conclusions;  and 
we  therefore  venture  to  mention  a  few  circumstances 
which  seem  irreconcilable  with  Mr  Murray's  inge- 
nious theory.  The  hop  fly  (Jlphis  humuli\  we  think, 
neither  does,  nor  (for  want  of  appropriate  organs) 
can,  feed  on  the  honey-dew;  and  if  -it  did,  this  feed- 
ing would  prove  rather  beneficial  than  otherwise  to 
the  plant,  by  clearing  it  from  the  leaves  whose  respi- 
ratory functions  it  obstructs.  So  far  from  feeding  on 
diseased  plants,  an  aphis  only  selects  the  youngest 
and  most  healthy  shoots,  into  the  tender  juicy  parts  of 
which  it  thrusts  its  beak  (haustellutn) ,  which  in  some 
species  is  much  longer  than  the  body,  and  no  more 
fitted  for  lapping  honey-dew  than  the  bill  of  JEsop's 
crane  was  for  eating  out  of  a  shallow  plate.  Jn  the 
experiment,  tried  by  Mr  Murray,  of  wiping  a  leaf, 
might  not  the  leaf  have  been  previously  wounded, 
perhaps,  by  the  beak  of  some  aphis,  and  hence  the 
exudation  of  sap,  not  honey-dew?  and  may  not  the 
circumstance  of  his  finding  the  honey-dew  on  leaves 
where  there  were  no  aphides  be  accounted  for  on 
the  principle  that  the  aphides  had  abandoned,  as  they 
always  do,  the  parts  covered  with  their  ejecta,  unless 
these  fell  from  insects  on  some  over-hanging  branch? 
It  is  justly  remarked  by  M.  Sauvages,  that  they 
are  careful  to  eject  the  honey-dew  to  a  distance 
from  where  they  may  be  feeding. "j"  We  have  now 
in  our  study  a  plant  of  the  Chinese  chrysanthemum 
(Jinthemis  Jlrtemisice  folia,  WILLD.),  the  young 

*  Treatise  on  Atmospherical  Electricity,  p.  147,  Lond.  1830. 
t  Trans.  Soc.  Roy.  de  Montpellier. 


-GENERATION    OF    INSECTS.  19 

shoots  of  which  have  swarmed  with  aphides  all  the 
winter,  and  the  leaves  below  are  covered  with  honey- 
dew.  We  tried  the  experiment  of  wiping  it  off  from 
a  leaf,  but  no  more  was  formed  when  it  was  protected 
by  a  piece  of  writing-paper  from  the  aphides  above; 
while  the  writing-paper  became  sprinkled  all  over 
•with  it  in  a  few  hours.  By  means  of  a  lens,  also,  we 
have  actually  seen  the  aphides  ejecting  the  honey  - 


The  almost  instantaneous  appearance  of  these  des- 
tructive insects  in  great  numbers  at  the  same  time,  is 
taken  notice  of  with  wonder  by  almost  every  writer. 
This  circumstance,  it  must  be  confessed,  gives  con- 
siderable plausibility  to  the  notion  of  their  being 
brought  by  winds,  —  for  whence,  we  may  be  asked, 
-could  they  otherwise  come  ?  Simply,  we  reply,  from 
the  eggs  deposited  the  preceding  autumn,  which,  hav- 
ing all  been  laid  at  the  same  time,  and  exposed  to  the 
same  degrees  of  temperature,  are  of  course  all  simul- 
taneously hatched.  In  the  case  of  the  aphides,  also, 
the  fecundity  is  almost  incalculable.  Reaumur  pro- 
ved by  experiment,  that  one  aphis  may  be  the  pro- 
genitor of  5,904,900,0^0  descendants  during  its  life; 
and  Latreille  says,  a  female  during  the  summer 
months  usually  produces  about  twenty-five  a  day. 
Reaumur  further  supposes,  that  in  one  year  there 
imy  be  twenty  generations.  We  ourselves  have 
counted  more  than  a  thousand  aphides  on  a  single  leaf 
of  the  hop;  and  in  seasons  when  they  are  abundant  — 
when  every  hop-leaf  is  peopled  with  a  similar  swarm 
—  the  number  of  eggs  laid  in  autumn  must  be,  to  use 
the  words  of  Good,  '  myriads  of  myriads.'  The  pres- 
ervation and  hatching  of  these  eggs  in  the  ensuing 
spring  must,  it  is  obvious,  depend  on  the  weather  and 

*  J.  R. 


20  INSECT    TRANSFORMATIONS. 

other  accidental  circumstances,  seldom  appreciable  by 
our  most  minute  observations. * 

The  history  of  other  insects,  erroneously  referred  to 
blighting  winds,  is  more  easily  traced,  from  their 
being  of  a  larger  size  than  the  aphides.  The  cater- 
pillar for  example,  of  L  >zotcenia  Rosarta,  mentioned 
before,  which  rolls  the  leaf  of  the  rose-tree,  is  one  of 
this  kind.  It  is  well  known  as  furnishing  the  common 
poetical  comparison  of  '  a  worm  i'  the  bud.'  Early 
in  autumn  the  mother  insect  deposits  an  irregularly 
oval-patch  of  yellowish  eggs,  covered  with  a  cement 


Two  groups  of  eggs  of  the  Ro!»e-leaf  roller  (Lozotcsnia  Rosa- 
na)  on  a  pane  of  glass. 

*  J.  R. 


GENERATION    OF    INSECTS.  21 

of  the  same  colour,  sometimes  upon  the  branches  of 
the  rose-tree,  but  more  frequently,  as  we  have  ob- 
served, upon  some  smooth  object  contiguous.  For 
several  successive  seasons,  we  have  found  more  than 
one  group  of  these  eggs  upon  the  glass  panes,  as 
well  as  the  frame  work,  of  a  window,  beneath  which 
a  rose-tree  has  been  trained.  At  present  (January 
1830)  there  are  two  of  these  groups  on  one  pane, 
and  three  on  the  frame-work;  and  as  each  contains 
about  fifty  eggs,  should  they  all  be  successfully  hatch- 
ed, two  or  three  hundred  caterpillars  would  at  once  be 
let  loose,  and,  streaming  down  simultaneously  upon  the 
rose-tree  beneath,  would  soon  devour  the  greater 
number  of  its  buds.  As  the  window  faces  the  east, 
the  sudden  appearance  of  the  insects  would  make  it 
appear  not  unplausible  that  they  had  been  swept  hither 
by  an  easterly  wind. 

We  found,  during  the  same  winter,  an  extraordina- 
ry number  of  similar  groups  of  the  eggs  of  a  leaf- 
roller  (Lozolcenia  Ribeana?)  on  the  branches  of  the 
gooseberry  and  red-currant,  in  a  garden  at  Lee. 
On  some  small  trees,  from  two  to  ten  groups  of  eggs 
were  discovered;  and  as  each  group  consisted  of 
from  thirty  to  fifty,  a  caterpillar  might  have  been 
hatched  for  every  bud.  After  the  severity  of  the 
season  was  over,  we  had  the  piece  of  bark  cut  off 
on  which  these  eggs  were  attached;  and  though  they 
had  been  exposed  on  the  bare  branches  to  the  intense 
frosts  of  1 829-30,  they  were  hatched  in  a  few  days 
after  being  brought  into  our  study.  As  the  currant- 
trees  were  not  then  come  into  leaf,  we  had  no  food  to 
supply  them  with,  and  they  refused  the  leaves  of  all 
other  plants  which  we  offered  to  them.  Had  they 
been  permitted  to  remain  on  the  trees  till  they  were 
hatched,  they  would  probably  have  not  left  a  single 
leaf  undevoured.  For  this  spring,  at  least,  these 
currant  bushes  will  be  safe  from  their  attacks,  and  of 


22  INSECT    TRANSFORMATIONS. 

course  will  set  at  defiance  the  supposed  blighting 
winds,  which  no  doubt  will,  as  usual,  be  accused  of 
peopling  the  adjacent  gardens  with  caterpillars.  It 
may  be  well  to  remark,  that  these  caterpillars,  when 
hatched,  are  scarcely  so  thick  as  a  thread  of  sewing 
silk,  and  being  of  a  greenish  colour,  they  are  not  read- 
ily found  on  the  leaves,  the  opening  buds  of  which  they 
gnaw  to  the  very  core.* 

It  does  not  seem  to  have  ever  occurred  to  those 
who  thus  speak  of  insectiferous  winds,  that  they  get 
rid  of  no  difficulty  by  the  supposition;  for  where,  we 
may  ask,  is  the  east  or  any  other  wind  to  take  up 
the  insects  or  eggs  which  it  is  said  to  drift  along? 
The  equally  sudden  disappearance  of  insects  all  at 
once,  which  is  also  popularly  attributed  to  winds,  arises 
from  their  having  arrived  at  maturity,  and  fulfilled  the 
designs  of  Providence,  by  depositing  their  eggs  for 
the  ensuing  season,  when  they  all  die,  some  in  a  few 
hours,  though  others  survive  for  several  days,  but 
rarelv  for  weeks. 

The  sudden  and  simultaneous  appearance  of  great 
numbers  of  frogs,  snails,  and  other  land  animals,  has 
given  rise  to  the  extravagant  opinion  that  they  have 
fallen  in  a  shower  frcm  the  clouds;  and  some  goodly 
theories  have  been  devised  to  account  for  the  pro- 
bable ascent  of  frog-spawn,  and  the  eggs  of  snails, 
into  the  atmosphere  by  whirlwinds.  The  impossi- 
bility of  this,  in  consequence  of  their  specific  gravity, 
is  of  course  left  out  of  consideration  by  the  theorists. 
Our  distinguished  naturalist,  Ray,  when  riding  one 
afternoon  in  Berkshire,  was  much  surprised  at  seeing 
an  immense  multitude  of  frogs  crossing  his  path,  and 
on  looking  into  the  adjacent  fields  he  found  that  two 
or  three  acres  of  ground  were  nearly  covered  with 
them.  They  were  all  proceeding  in  the  same  direc- 
tion towards  some  woods  and  ditches;  and  he  traced 

*  J<R, 


GENERATION    OF    INSECTS,  23 

them  back  to  the  side  of  a  very  large  pond,  which,  in 
spawning  time,  he  was  informed,  swarmed  with  count- 
less numbers  of  frogs.  He  naturally  concluded,  there- 
fore, that,  instead  of  having  been  precipitated  from  the 
clouds,  they  had  been  bred  in  the  pond,  from  which 
they  had  been  invited  a  short  time  before,  by  a  re- 
freshing shower,  to  go  in  quest  of  food. *  Their  great 
numbers  will  appear  less  marvellous,  when  we  consid- 
er that  a  single  frog  spawns,  as  De  Montbeillard  in- 
forms us,  about  1300  eggs.|  Were  it  not,  indeed, 
for  their  numerous  enemies,  and  their  not  being  fit  to 
propagate  till  they  are  three  years  old,  the  country 
would  soon  be  overrun  with  these  reptiles.  We  have 
more  than  once  seen  a  similar  legion  of  hair-worms 
( Gordii  aqualici,  LINN.)  in  a  garden  at  Lee,  in  Kent,, 
every  plant  and  spot  of  ground  literally  swarming  with 
them.  Their  numbers,  however,  were  easily  account- 
ed for,  as  a  stream  at  the  bottom  of  the  garden 
abounds  with  them,  and,  like  frogs,  they  appear  to  be 
amphibious  J 

The  errors  of  theory,  as  well  as  the  mistakes  of 
observers,  swayed  (unconsciously  perhaps)  by  the 
influence  of  their  theoretical  opinions,  may  all  be 
traced,  we  think,  to  the  propensity  of  human  nature 
to  discover  resemblances  in  things,  which  are  after- 
wards magnified  into  close  affinity,  or  even  into 
identity.  We  are  indebted  to  one  of  our  best  living 
entomologists,  Mr  W.  Mac  Leay,  for  clearly  point- 
ing out  the  broad  distinction  between  analogy  and 
affinity.^  The  supposed  floating  of  the  eggs  of  insects 
in  the  air  thus  appears  to  have  originated  in  drawing 
an  analogy  from  the  seeds  of  plants;  though,  from 
the  facts  we  have  stated,  so  far  from  there  being  any 

*  Ray's  Wisdom  of  God  in  the  Creation,  p.  156. 
t  Diet.  Classique  d'Hist.  Nat,  vii,  p.  495.  t  J-  &• 

$  Hora?  Entomologies,  or  Essays  on  Annulose  Animals,  8v(K 
London,  1819-21. 


24  INSECT    TRANSFORMATIONS. 

analogy,  there  is  no  difference  more  marked  than  in 
this  very  point  —  that  the  eggs  of  insects  are,  in  most 
cases,  fixed  by  a  glue  at  the  moment  of  exclusion, 
while  the  seeds  of  plants  are  no  less  uniformly 
diffusable  and  free.  The  fertile  seeds  of  plants, 
it  is  true,  are  heavy  enough  to  sink  in  water,  and 
consequently  as  much  unfitted  for  floating  in  the 
air  as  the  eggs  of  insects;  but  the  contrivances  to 
counteract  this  exemplify  some  of  the  most  beautiful 
provisions  of  nature.  The  diffusion  of  the  seeds  of 
thistles,  groundsel,  dandelion,  &c,  by  means  of  feath- 
ery down,  attracts  the  notice  of  the  most  incurious. 
Another  contrivance  of  nature  for  effecting  the  same 
purpose  is  not  only  curious  in  itself,  but  bears  upon 
our  present  subject  as  illustrating  an  affinity  which  it 
may  be' supposed  to  have  with  the  ovipositing  of  certain 
insects. 

The  seeds  of  the  various  species  of  violets  are 
contained  in  a  capsule  of  a  single  cell,  or  loculament, 
consisting,  however,  of  three  valves.  To  the  inner 
part  of  each  of  these  valves  a  seed  is  attached,  und 
it  remains  so  for  some  time  after  the  valves,  in  the 
process  of  ripening,  have  separated  and  stood  open. 
The  influence  of  the  sun's  heat  causes  the  sides  of 
each  valve  to  shrink  and  collapse;  and  in  this  state 
the  edges  press  firmly  upon  the  seed;  which,  it  may 
be  remarked,  is  not  only  extremely  smooth,  polished, 
and  shining,  but  regularly  egg-shaped.  Thus,  when 
the  collapsing  edge  of  the  valve  slides  gradually 
and  forcibly  down  over  the  sloping  part  of  the  seed, 
it  is  thrown  with  a  jerk  to  a  considerable  distance 
There  is  another  part  of  the  contrivance  of  nature  for 
the  same  purpose,  in  the  violacese,  worthy  of  remark. 
Before  the  seed  is  ripe,  the  capsule  hangs  in  a  droop- 
ing position,  with  the  persisting  calyx  spread  over  it 
like  an  umbrella,  to  guard  it  from  the  rain  and  dews, 
which  would  retard  the  process  of  ripening:  but  no 


DISPERSION    OF    SEEDS.  25 

sooner  is  the  ripening  completed,  than  the  capsule 
becomes  almost  upright,  with  the  calyx  for  a  support. 
This  position  appears  to  be  intended  by  nature  to  give 
more  effect  to  the  valvular  mechanism  for  scattering 
the  seeds,  as  the  capsule  thus  gains  a  higher  eleva- 
tion (in  some  cases  more  than  an  inch)  from  which 
to  project  them.  Some  ripe  capsules  of  a  fine  variety 
of  heart's-ease  ( Viola  tricolor},  which  I  placed  in  a 
shallow  pasteboard  box,  in  a  drawer,  were  found  to 
have  projected  their  seeds  to  the  distance  of  two  feet. 
From  the  elevation  of  a  capsule,  therefore,  at  the  top 
of  a  tall  plant,  these  seeds  might  be  projected  twice 
or  thrice  that  distance.* 

We  may  mention,  as  another  very  curious  illustra- 
tion of  the  power  in  plants  of  discharging  their  seeds, 
the  remarkable  instance  of  a  minute  fungus  ( Sphcero- 
bolus  stellatusy  TODE).  This  plant  has  the  property 
of  ejecting  its  seeds  with  great  force  and  rapidity, 
and  with  a  loud  cracking  noise ;  and  yet  it  is  no  big- 
ger than  a  pin's  head.f 

The  circumstance  alluded  to  as  analogous  in  in- 
sects to  this  admirable  contrivance,  occurs  in  the 
forcible  discharge  of  the  eggs  of  some  species  to  a 
distance.  The  ghost  moth  (Hepialus  humuli),  for 
example,  ejects  its  minute  black  eggs  with  so  much 
rapidity,  that  De  Geer  describes  them  as  running 
from  the  oviduct;  and  they  are  sometimes  for- 
cibly thrown  out  like  pellets  from  a  pop-gun. J 
c  A  friend  of  mine,'  says  Kirby,  '  who  had  observed 
with  attention  the  proceedings  of  a  common  crane- 
fly  (Tipula\  assured  me,  that  several  females  which 
he  caught  projected  their  eggs  to  the  distance  of 
more  than  ten  inches. '§  Another  instance  is  men- 

*  J.  R.  in  Mag.  of  Nat.  Hist.,  i.  380. 

t  For  a  minute  account  of  this  singular  plant,  see  Grevill's 
Scottish  Cryptogamic  Flora,  No.  xxxii. 
t  De  Geer,  Mem.  des  Insects,  iv,  494. 
§  Kirby  arid  Spence,  Intr.  iii,  66. 
TOL.   VI.  3 


26  INSECT    TRANSFORMATIONS. 

tioned  by  the  Abbe  Preaux,  of  a  four-winged  fly, 
called  by  him,  Mouche  baliste,  which,  when  caught, 
jets  out  its  eggs  at  intervals,  as  if  by  the  jerk  of  a 
spring.* 

The  apparent  analogy,  however,  between  these  in- 


A,  Plants  of  Sphcerobofus,  natural  size.  B,  magnified  view. 
C,  sectional  view,  with  the  seed  just  previous  to  projection.  Dr 
the  seed  in  the  act  of  projection.  E,  a  plant  immediately  after 
projection  ;  a,  the  seed  ;  6  6,  a  line  indicating  its  course. 


*  Diet.  Classique  d'Hist.  Nat.,  Art.  MOUCHES  BALISTES. 
The  words  are  *  Insecte  a  quatre  ailes,  qui  lance  ses  oeufs  a  di- 
verses reprises,  et  comme  par  un  ressort,  lorsqu'on  le  saisit.' 


DISPERSION    OF    SEEDS.  27 

sects  and  the  plants  which  discharge  their  seeds, 
will  disappear,  when  we  consider  that  the  scattering 
of  the  seeds  is,  in  the  plants,  a  regular  and  con- 
stant process  of  nature;  whereas  the  insects  only  jet 
out  their  eggs  from  fear  when  caught.  The  power 
of  throwing  their  eggs  to  a  distance,  indeed,  could 
be  of  no  possible  use  to  insects,  because  they  pos- 
sess the  more  efficient  power  of  locomotion. 

The  facts  which  we  have  thus  stated  with  regard 
to  the  seeds  of  plants  being  diffused  by  the  means 
of  winged  down,  or  by  the  more  remarkable  capacity 
of  being  projected,  differ,  as  we  have  shown,  in  some 
important  circumstances  from  the  nearly  similar  ar- 
rangement of  nature  in  the  economy  of  insects. 
They  constitute  affinities,  but  not  analogies.  On  the 
other  hand,  the  more  universal  law  of  the  conti- 
nuance of  insect  life  by  every  new  generation  being 
hatched  from  eggs,  may  be  illustrated  by  an  analogy, 
which  is  observed  even  in  the  most  minute  instances, 
in  the  generation  of  plants  from  seeds. 

The  diffusion  of  the  seeds  of  an  extensive  order 
of  plants  (CryptogamicB)  LINN.,  Jlcotyledones ,  Juss., 
CellulareSj  DE  CANDOLLE)  being  so  universal,  and 
the  seeds  (sporules)  themselves  being  so  minute  as 
to  elude  common  observation,  the  phenomena  thence 
arising  have,  like  the  sudden  appearance  of  newly 
hatched  insects,  given  some  colour  to  the  doctrine  of 
spontaneous  generation.  We  may  see  this  exem- 
plified every  day  on  brick  walls  recently  built,  even  if 
they  be  covered  with  a  smooth  coat  of  cement.  The 
first  indication  of  vegetable  life  on  such  a  wall,  par- 
ticularly in  parts  exposed  to  the  trickling  down  of 
rain  water,  is  that  of  a  green  silky-looking  substance, 
having  somewhat  the  appearance  of  a  coat  of  green 
paint.  Mr  Drummond,  of  the  Cork  Botanic  Garden, 
by  accurately  watching  the  progress  of  this  green 
matter,  which  had  been  unsuccessfully  investigated 


28  INSECT   TRANSFORMATIONS. 

by  Priestley,  Ingenhouz,  and  Ellis,  and  had  been 
mistaken  by  Linnaeus  for  a  crop  of  byssi,  ascertain- 
ed beyond  question  that  it  always  consisted  of  the 
minute  buds  of  common  mosses,  such  as  the  wall 
screw  rnoss  (  Tortula  muralis)  and  the  common  hair- 
hood  moss  (Polytrichum  commune)  *  At  Glasgow, 
we  have  repeatedly  remarked,  that  on  the  walls  of 
houses,  built  with  freestone  raised  from  a  quarry  more 
than  a  hundred  feet  under  the  surface  of  the  soil, 
the  whole  exterior  would,  in  the  course  of  one  month, 
appear  as  green  as  if  painted,  with  these  innumera- 
ble germinating  mosses. "f 

The  germination  of  mosses  on  walls  appears  to 
arise  from  the  seeds  (sporules)  being  carried  into  the 
air.  This  process  is  facilitated  by  their  extreme 
minuteness  and  their  comparative  lightness,  for  they 
do  not  sink  in  water  like  the  seeds  of  phenogamous 
plants  and  the  eggs  of  insects,  as  appears  from  their 
germinating  on  the  surface  of  stagnant  water  as  fre- 
quently as  on  walls.  In  low  situations,  the  mode  in 
which  the  seeds  of  cryptogamic  plants  are  diffused 
is  well  exemplified  in  the  puff-ball  (Lycoperdon), 
which,  when  ripe,  explodes  its  sporules  in  the  form 
of  a  smoke-like  cloud.  Mosses  again,  which  grow 
on  trees  and  walls,  if  they  do  not  thus  explode  their 
sporules,  must  drop  them  into  the  air;  and,  as  they 
chiefly  ripen  early  in  spring,  the  winds  which  then 
prevail  will  scatter  them  to  considerable  distances. 
.But  we  only  state  this  as  a  highly  probable  inference 
from  Drummond's  discovery:  to  detect  these  all  but 
invisible  seeds  floating  in  the  atmosphere,  and  trace 
them  in  their  passage  from  the  parent  plant  to  the  wall 
or  tree  where  they  begin  to  germinate,  we"  think  is 
hardly  possible. 

If  the  doctrine  be  sound,  that  every  plant  arises 
from  seed,  we  must  either  believe  that  innumerable 

*Linn.  Trans.  t  J.  R. 


DISPERSION    OF    SEEDS.  29 

mosses  are  wafted  to  the  walls  through  the  air,  or 
adopt  the  hypothesis  that  they  have  existed  for  cen- 
turies in  the  interior  of  the  rocks  of  the  quarry.  That 
it  is  not  impossible  the  seeds  may  have  existed  in  the 
rocks,  several  curious  facts  would  lead  us  to  believe. 
Some  seeds,  for  example,  retain  the  power  of  germi- 
nating for  an  indefinite  length  of  time;  since  the 
wheat  usually  wrapt  up  with  Egyptian  mummies  will 
often  germinate  and  grow,  as  well  as  if  it  had  been 
gathered  the  preceding  harvest.  It  also  bears  upon 
this  subject,  that  when  a  piece  of  ground,  which  has 
never  been  tilled,  is  turned  up  by  the  spade  or  the 
plough,  it  immediately  becomes  covered  with  a  crop 
of  annuals,  not  one  of  which  may  grow  within  many 
miles  of  the  spot;  and  a  number  of  them,  such  as 
hedge  mustard  (Sisymbrium  officinale)  and  chick- 
weed  (Jllsine  media],  whose  seeds  are  not  winged. 
It  is  no  less  worthy  of  remark  that  all  these  annuals 
will  again  disappear  as  soon  as  the  grass  is  suffered 
to  spread  over  the  spot  which  has  been  dug  up.  It 
is  mentioned  by  Mr  James  Jennings,  in  Time's  Tele- 
scope for  1823,  that  the  coltsfoot  (  Tussilago  farfara) 
is  usually  the  first  plant  which  appears  in  England  in 
such  cases — a  circumstance  by  no  means  remarkable, 
as  the  seeds  of  this  plant  are  winged  with  down,  and 
extremely  light. 

A  still  more  minute  family  of  cryptogamio  plants, 
and  consequently  more  difficult  to  trace,  is  well  known 
by  the  popular  name  of  mould  or  mouldiness  (Mu- 
cedines,  LINN.)  This,  Adolphe  Brongniart  justly 
remarks,  is,  in  one  of  its  groups,  nearly  allied  to  the 
puff-balls  (Ly coper da) ,  whose  mode  of  diffusing  their 
seeds  we  have  just  described.  When  mould  is  exa- 
mined by  the  microscope  it  is  seen  to  resemble  these; 
and  sometimes  various  fungi  are,  when  mature,  filled 
with  a  blackish  dust,  supposed  to  be  the  seed.  Mi- 
cheli,  of  Florence,  an  eminent  botanist,  resolved  to 

VOL.  vi.  3* 


30 


INSECT    TRANSFORMATIONS. 


try  whether  this  supposed  seed  would  grow  if  sown  on 
vegetable  substances,  and  found  that  it  did  so.  On 
his  experiments  being  repeated  at  Bologna,  however, 
it  was  discovered  that  the  mould  grew  equally  well 
where  none  of  the  black  powder  bad  been  sown;  but 
Spallanzani,  by  more  accurate  attention,  confirmed  the 
conclusion  of  Micheli.  He  collected  a  great  quan 
tity  of  the  dust,  and,  taking  a  number  of  pieces  of 
moistened  bread,  apples,  pears,  gourds,  &c,  sowed 
some  thickly,  others  sparingly,  and  others  not  at  all. 
The  result  was,  that  on  the  unsown  substances  the 
mould  did  appear,  but  several  days  later,  and  then 
greatly  less  in  quantity,  than  on  the  sown  substances; 
while  of  these  two,  the  pieces  thickly  sown  had  more 
than  double  the  quantity  of  the  pieces  thinly  sown, 
though,  when  it  came  up  thick,  it  did  not  grow  so 
tall. 


Microscopic  views  of  apple  and  pear  mould.  A  A,  Part  of  a  shrivelled 
apple,  covered  with  mould  on  the  inside,  a  a  a  «,  several  of  the  indivi- 
dual mould  plants  highly  magnified.  6,  a  branched  one.  c  t/,  seed-ves- 
sels, one  bursting  and  scattering  its  seed,  e,  one  mushroom-shaped.  /*,  a 
portion  of. pear  mould,  of  a  branched  form. 

We  were  much  struck  last  autumn  (1829),  upon 
cutting  an  apple  asunder,  to  find  in  the  seed-cells  a 


DISPERSION    OF    SEEDS.  31 

copious  growth  of  the  mould  with  the  slender  stems 
and  globular  heads  figured  by  Spallanzani.  Mould 
upon  an  apple  is  not  indeed  wonderful;  but  the  one 
in  question  was  not  only  large,  but  apparently  sound 
throughout.  Whence,  then,  came  the  seeds  of  this 
mould  in  the  very  core  of  the  apple  ?  We  have  also 
met  with  mould  of  a  different  species,  resembling  the 
green  mould  on  the  rind  of  oranges  (Jlcrosporium  fas- 
ciculatum,  GREVILLE),  even  on  the  kernels  of  nuts, 
when  there  was  no  opening  save  the  minute  pores  in 
the  shell.  Through  these  pores,  then,  after  being 
stripped  of  the  husk  that  covered  them,  the  seed  of 
this  nut-mould  must  have  entered.  This,  however, 
will  not  account  for  the  mould  in  the  apple ;  the  seed 
of  which,  we  think,  must  have  been  introduced  while 
it  was  in  embryo,  in  some  such  way  as  the  seeds  of 
the  subcortical  fungi  so  abundant  on  dead  leaves 
and  branches  of  trees.  This  again  may  be  illustrated 
by  the  curious  facts  respecting  substances  found  in  the 
interior  wood  of  trees.  Sir  John  Clark,  for  example, 
tells  us  that  the  horns  of  a  large  deer  were  discovered 
in  the  heart  of  an  oak  in  Whinfield  Park,  Cumber- 
land, fixed  in  the  timber  with  large  iron  cramps,  with 
which,  of  course,  it  had  at  first  been  fastened  on  the 
outside.*  The  eminent  naturalist,  Adanson,  on  visit- 
ing Cape  Verd,  was  struck  with  the  venerable  aspect 
of  a  tree  fifty  feet  in  circumference;  and  recollecting 
having  read  in  some  old  voyages  that  an  inscription 
had  been  made  upon  such  a  tree,  he  was  induced  to 
search  for  this  by  cutting  into  the  wood,  and,  marvel- 
lous to  say,  he  actually  found  it  under  300  layers  of 
wood!*  De  Candolle,  one  of  the  greatest  living  bota- 
nists, remarked  '  a  frost-bitten  part  in  the  wood  of  a 
tree,  cut  down  in  1800,  in  the  forest  of  Fontainebleau. 
This  being  covered  with  9 1  layers  of  wood,  indicated 

*  Phil.  Trans.,  vol.  xli,  p.  448.    - 
t  Adanson,  Voyages  a  Senegal. 


32  INSECT   TRANSFORMATIONS. 

that  the  accident  occurred  in  1709,  so  remarkable  for 
a  severe  frost.  '*  With  these  facts  before  us,  we  think 
the  introduction  of  the  seed  of  the  mould  into  the  cen- 
tre of  the  apple  by  no  means  so  unaccountable  as  at 
first  view  it  appeared.  Be  this  as  it  may,  we  tried, 
with  the  seed  gathered  from  this  apple-mould,  similar 
experiments  to  those  of  Spallanzani,  with  results  pre- 
cisely similar  to  his;  and  being  in  this  way  able  at 
pleasure  to  produce  mould  of  the  same  species  by 
sowing,  we  are  entitled  to  conclude  that  all  mould 
arises  from  seed,  otherwise  nature  must  produce  the 
same  effect  from  dissimilar  causes,  which  is  contrary 
to  the  first  principles  of  sound  philosophy. | 

*  Conv.  on  Veg.  Physiol.,  i,  59.  t  J.  &• 


CHAPTER  II. 

Physiology  of  Insects'  Eggs.  —  Their  Colour,  Structure,  Shape,  Size, 
and  Number. 

IT  was  a  notion  of  Darwin's,  (much  more  ingenious 
and  plausible  than  his  metamorphoses  of  shell-fish  into 
birds,)  that  the  variety  in  the  colours  of  eggs,  as  well 
as  the  colours  of  many  animals,  is  adapted  to  the  pur- 
poses of  concealment  from  their  natural  enemies. 
Thus,  he  says,  the  snake,  the  wild  cat,  and  the  leopard, 
are  so  coloured  as  to  resemble  dark  leaves  and  their 
lighter  interstices;  birds  resemble  the  colour  of  the 
brown  ground  or  the  green  hedges  which  they  frequent; 
"While  moths  and  butterflies  are  coloured  like  the  flowers 
which  they  rob  of  their  honey. *  By  following  up 
this  curious  theory,  Gloger,  a  German  naturalist  ,f  has 
remarked,  that  those  birds  whose  eggs  are  of  a  bright 
or  conspicuous  colour  instinctively  conceal  their  nests 
in  the  hollows  of  trees,  never  quit  them  except  during 
the  night,  or  sit  immediately  after  they  have  laid  one 
or  two  eggs.  On  the  other  hand,  in  the  case  of  birds 
who  build  an .  exposed  nest,  the  colours  of  the  eggs 
are  less  attractive.  Amongst  birds  whose  eggs  are 
perfectly  white  —  the  most  conspicuous  of  all  colours, 
—  he  instances  the  kingfisher  (Jttcedo\  which  builds 
in  a  hole  in  a  river's  bank;  the  woodpecker  (Picus), 
which  builds  in  the  hole  of  a  tree;  and  the  swallow 

*  Zoonomia,  Sect.  39,  p.  248,  3d  ed.,  and  Botan.  Garden, 
note  on  Rubia. 

t  Verhand.  der  Gesellsch.  Naturforsch.  Freunde.  Berlin, 
1824. 


34  INSECT    TRANSFORMATIONS. 

(Hirundo  domeslica)^  whose  nest  has  a  very  small 
opening:  while  owls  and  hawks,  which  scarcely  quit 
their  nests  in  the  day,  and  pigeons,  which  only  lay  one 
or  two  eggs  and  sit  immediately  after,  have  also  white 
eggs.  The  bright-blue,  or  bright-green  egg,  again, 
belongs  to  birds  which  build  in  holes,  as  the  starling 
(Sturnus  vulgaris),  or  which  construct  their  nests  of 
green  moss,  or  place  them  in  the  midst  of  grass,  but 
always  well  covered.  Almost  all  singing  birds,  he  al- 
leges, lay  eggs  of  a  dull  or  dark  ground,  and  various- 
ly speckled;  and  they  for  the  most  part  build  open 
nests  with  materials  similar  in  colour  to  the  eggs,  so 
that  no  evident  contrast  is  presented  which  might  lead 
to  their  discovery  and  destruction.  We  may  add  from 
.Darwin  the  examples  of  the  hedge-sparrow  (Accentor 
modularis),  whose  eggs  are  greenish  blue,  as  are 
those  of  magpies  and  crows,  which  are  seen  from  be- 
neath in  wicker  nests,  between  the  eye  and  the  blue 
of  the  firmament.* 

As  this  theory  is  but  indirectly  connected  with  ouf 
subject,  we  cannot  here  spare  room  to  examine  it  ; 
but  we  may  remark,  that  it  appears  to  us  much  more 
beautiful  and  ingenious  than  true:  for  we  could  enu- 
merate more  instances  in  which  the  principle  fails 
than  holds  good.  Gloger's  instances  also  are  far 
from  accurate;  for  though  the  king-fisher,  for  example, 
hides  her  shining  white  eggs  in  a  hole,  yet  that  will 
not  conceal  them  from  the  piercing  eyes  of  their  chief 
enemy,  the  water  rat,  which,  like  all  burrowing  ani- 
mals, can  see  with  the  least  possible  light.  Many 
birds,  also,  which  lay  bright-coloured  eggs,  make 
open  nests;  the  thrush, .for  example,  whose  clear-blue 
eggs,  with  a  few  black  blotches,  are  far  from  being 
concealed  by  the  plastering  of  clay  and  cow-dung 
upon  which  they  are  deposited.  The  green  finch 

*  See  also  St  Pierre;  Studies  of  Nature,  ii,  393  ;  Note. 


COLOURS    OF    EGGS.  35 

(Fringi'la  chloris,  TEMMINCK),  again,  which  builds 
an  open  nest  of  green  moss,  lined  with  horsehair, 
black  or  white  as  it  can  be  had,  lays  clear  white  eggs 
with  red  spots,  precisely  like  those  of  the  common 
wren  and  the  willow  wren  (Sylvia  Trochilus),  which 
build  covered  nests  with  a  small  side-entrance;  while 
the  house-sparrow  (Fringilla  domestica)  lays  eggs  of 
a  dull,  dirty  green,  streaked  with  dull  black,  and  al- 
ways builds  in  holes  or  under  cover.  These  objec- 
tions will  render  it  unnecessary  for  us  to  follow  Darwin 
into  his  fanciful  account  of  the  origin  of  the  colour  of 
eggs,  which  he  ascribes  to  the  colour  of  the  objects 
amongst  which  the  mother  bird  chiefly  lives  acting 
upon  the  shell  through  the  medium  of  the  nerves  of 
the  eye ;  for,  if  this  were  correct,  we  should  have  the 
green-finch  and  the  red-breast,  instead  of  their  white 
eggs,  laying  blue  ones  like  the  hedge-sparrow  and  the 
firetail. 

Upon  a  partial  view  of  the  subject,  we  might  bring 
many  facts  to  support  the  theory  from  the  colour  of 
the  eggs  of  insects.  The  nettle  butterflies,  for  ex- 
ample, the  small  tortoise  shell  (Vanessa  Urticce),  the 
peacock  (V.  Jo),  and  the  admirable  (V.  Atalanla) , 
all  lay  eggs  of  a  green  colour,  precisely  similar  in 
tint  to  the  plant  to  which  they  are  attached.  On  the 
contrary,  the  eggs  of  the  miller  moth  (Jlpatela  Lepo- 
Tina,  STEPH.),  which  are  deposited  on  the  gray  bark 
of  the  willow,  are  light  purple;  another  beautiful  geo- 
metric moth  (Geometra  illunaria),  which  Sepp*  calls 
Hercules je,  lays  its  pink  eggs  in  the  fissures  of  the 
bark  of  the  elm ;  the  puss  moth  ( Cerrura  vinula) 
lays  shining  brown  eggs  on  the  green  leaf  of  the  pop- 
lar; and  the  garden  white  butterfly  (Pontia  Brassicce) 
lays  a  group  of  yellow  ones  on  a  green  cabbage  or  cole- 
wort  leaf,  but  not  of  so  bright  a  yellow  as  those  of  the 
seven-spot  ladybird  (Coccinella  Septempunctata), 

*  Sepp,  der  Wonderen  Gods,  Tab.  35. 


36  INSECT    TRANSFORMATIONS. 

patches   of  which  may  be  found  on  many   sorts  of 
leaves  during  the  summer  months. 

The  immediate  origin  of  colour  in  the  eggs  of  in- 
sects is  in  some  cases  the  enclosed  yolk  shining  through 
the  transparent  shell;  but  in  others,  the  shell  is  not 
uniformly  transparent,  but  ringed,  banded,  or  dotted 
with  opacities  of  various  colours.  In  the  eggs  of  the 
drinker  moth  (Odonestis  potaioria),  for  example,  there 
are  two  circular  rings  of  a  green  colour,  from  the 
green  yolk  appearing  through  the  shell;  while  the 
rest  of  the  shell  is  white  and  opaque,  as  we  have  prov- 
ed by  dissection.*  Certain  ruddy  spots  on  the  white 
eggs  of  the  small  rhinoceros  beetle  (  Oryctes  nasicornis, 
ILLIGER)  were  discovered  by  Swammerdam  to  be  the 
red  mandibles  and  spiracles  of  the  unhatched  grub 
seen  through  the  shell;  and  the  white  ground,  we  in- 
fer, was  similarly  caused  by  the  body  of  the  grub.| 
This,  however,  cannot  be  the  origin  of  the  bright  red 
spots  on  the  beautiful  yellow  egg  of  the  brimstone 
moth  (Rumia  cratcegata^  DUPONCHEL),  which  may, 
perhaps,  have  a  similar  origin  to  those  of  birds. 

With  respect  H;o  the  eggs  of  birds,  it  has  been  re- 
marked by  Mr  Knapp,J  that  in  those  '  of  one  hue, 
the  colouring  matter  resides  in  the  calcareous  part  ; 
but  where  there  are  markings,  these  are  rather  ex- 
traneous to  it  than  mixed  with  it.  The  elegant  blue 
that  distinguishes  the  eggs  of  the  fire-tail  ( Sylvia 
ph&nicurus,  LATH.),  and  of  the  hedge-sparrow, 
though  corroded  away,  is  not  destroyed  by  muriatic 
acid.  The  blue  calcareous  coating  of  the  thrush's 
egg  is  consumed;  but  the  dark  spots,  like  the 
markings  on  the  eggs  of  the  yellow-hammer,  house- 
sparrow,  magpie,  &,c,  still  preserve  their  stations  on 

*  J.  R. 

t  Swammerdam,  Book  of  Nature,  i,  J.3. 
t  Journal  of  a  Naturalist,  p.  230. 


SHELLS    OF    EGGS.  37 

the^  film,  though  loosened  and  rendered  mucilaginous 
by  this  rough  process.  Though  this  calcareous  mat- 
ter is  partly  taken  up  during  incubation,  the  mark- 
ings upon  these  eggs  remain  little  injured  even  to  the 
last,  and  are  almost  as  strongly  defined  as  when  the 
eggs  are  first  laid.  These  circumstances  seem  to  im- 
ply, that  the  colouring  matter  on  the  shells  of  eggs 
does  not  contribute  to  the  various  hues  of  the  plum- 
age; but,  it  is  reasonable  to  conclude,  are  designed  to 
answer  some  particular  object  not  obvious  to  us  :  for 
though  the  marks  are  so  variable,  yet  the  shadings 
and  spottings  of  one  species  never  wander  so  as  to 
become  exactly  figured  like  those  of  another  family, 
but  preserve  year  after  year  a  certain  characteristic 
figuring.7 

Most  of  these  remarks  will  apply  to  the  colours  of 
the  eggs  of  insects:  but  though  we  can  in  most  in- 
stances trace  no  connexion  between  the  colours  of 
eggs  and  the  perfect  insect,  there  is  a  striking  ex- 
ception in  the  egg  of  the  brimstone  moth  mentioned 
above,  which  corresponds  exactly  in  colour  with  the 
wings  of  the  moth,  though  the  caterpillar  is  of  a  dull 
brown. 

The  eggs  of  insects,  like  those  of  birds,  have  a 
shell  enclosing  the  germ  of  the  caterpillar  with  a 
peculiar  matter  for  its  nourishment,  like  the  white 
and  yolk  of  a  bird's  egg,  provided  for  the  nourishr- 
ment  of  the  contained  chick.  These  several  parts, 
however,  are  very  different  in  substance  from  the 
eggs  of  birds.  The  shell  of  the  bird's  egg  is  brittle, 
opake,  chiefly  composed  of  chalk  (carbonate  of 
/inie),  and  lined  with  a  very  thin  tough  membrane; 
while  in  the  egg  of  an  insect  the  shell  is  not  brittle,, 
is  transparent,  contains  no  lime  (for  it  is  not  per- 
ceptibly acted  upon  by  diluted  sulphuric  acid),  and 
no  lining  membrane  can  be  detected.  It  appears, 
indeed,  very  similar  to  the  transparent  portion  of  a 

VOL.  vi.  4 


38  INSECT    TRANSFORMATIONS. 

goose-quill  in  the  eggs  of  the  drinker  and  ether  moths 
which  we  have  dissected;*  but  in  the  eggs  which  are 
deposited  in  moist  places,  and  in  those  of  spiders,  it  is 
extremely  thin.t     The  eggs  of  saw-flies,  ants,  &c, 
which  grow  larger,  as  we  shall  afterwards  show,  du- 
ring the  process  of  hatching,  must  possess  an  expansi- 
ble shell  to  allow  of  their  enlargement.     The  yolk  and 
white  in  the   eggs  of  birds  are  separated  from  each 
other  by  a  very  fine  membranous  bag  in  which  each 
is  contained  ;  but  in  the  eggs  of  insects,  what  an- 
swers to  the  yolk  consists  of  distinct  minute  globules, 
which  float  in  the  white,  if  we  may  call  it  so,  for  it  does 
not,  as  we  have  ascertained,  coagulate  in  boiling  water. 
The  eggs  of  the  gypsey  moth   (Hypogymna  dispar), 
which  we  boiled,  still  continued  partly  fluid,  though 
the  brown  matter  answering  to  the  yolk  was  consider- 
ably thickened.     The  portion  which  does  not  thicken 
by  boiling  most  probably  forms  the  first  internal  fluids 
of  the  caterpillar,  answering  to  the  blood  of  quadru- 
peds.    The    point  where  the    caterpillar    originates, 
—  answering  to  the  scar  ( Cicatricula)  in  the  eggs  of 
birds,  —  we  can  readily  distinguish  even  by  the  naked 
eye  in  the  larger  species  of  eggs,  as  it  lies  always 
immediately  under  the    shell.*      '  Having  directed,' 
says  the  younger  Huber,  '  my  close  attention  to  the 
eggs  of  ants,  I  remarked  that  they  were  of  different 
sizes,  shades,  and  forms.     The  smallest  were  white, 
opaque,    and  cylindrical  ;    the   largest,    transparent, 
and  slightly   arched  at    both  ends  ;    while  those  of 
a  middle  size  were  semi-transparent.       On   holding 
them  up  to  the  light  I  observed  a  sort  of  white  ob- 
long cloud;  in  some,  a   transparent   point  might  be 
remarked   at   the    superior    extremity  ;  in   others,  a 
clear  zone  above  and  underneath  the  little  cloud.    The 
largest  presented  a  single  opaque  and  whitish  point 

*  J.  R.  t  Kirby  and  Spence,  Intr.  86. 


GERM    OF    EGGS.  39 

in  their  interior.  There  were  some  whose  whole  bo- 
dy was  so  remarkably  clear  as  to  allow  of  my  very  dis- 
tinctly observing  the  rings.  On  fixing  attention  more 
closely  upon  the  latter,  1  observed  the  egg  open,  and 
the  larva  appear  in  its  place.  Having  compared  these 
eggs  with  those  just  laid,  I  constantly  found  the  latter 
of  a  milky  whiteness,  completely  opaque,  and  smaller 
by  one-half,  so  that  I  had  no  reason  to  doubt  of  the 
eggs  of  ants  receiving  a  very  considerable  increase  in 
size;  that  in  elongating  they  become  transparent,  but 
do  not  at  this  time  disclose  the  form  of  the  grub,  which 
is  always  arched.'* 

The  germ  in  the  egg  of  the  garden  spider  (Epeira 
diadema)  is  described  by  the  accurate  Heroldt,  as 
appearing  to  the  eye  in  form  of  a  minute  white  point 
immediately  under  th*e  shell,  and  in  the  centre  of  the 
circumference.  On  examining  this  point  more  nar- 
rowly, it  is  found  to  be  of  a  lenticular  shape,  and 
composed  of  innumerable  whitish  granulations  of  a 
globular  form,  differing  only  from  the  globules  of  the 
yolk  in  being  smaller  and  more  opaque,  as  may  be 
seen  by  squeezing  out  the  contents  of  a  spider's  egg 
into  a  watch-glass.  The  most  singular  circumstance 
observed  by  Heroldt  was,  that  in  some  species  of  spi- 
ders an  egg  appeared  to  have  a  considerable  number 
dispersed  upon  different  points  of  the  surface;  but  all 
these  ultimately  united  into  a  single  germ.! 

The  eggs  of  the  glow-worm  (Lampyris  noctiluca), 
as  we  ascertained  from  those  deposited  by  one  which 
we  found  in  1829,  at  Rudesheim,  on  the  Rhine,  are 
golden  yellow,  somewhat  resembling  cherry-tree  gum, 
while  the  internal  substance  is  similar  in  consistence 

*  M,  P.  Huber  on  Ants,  p.  68. 

1  Heroldt,  Exercit.  de  Generat.  Aranearum  in  Ovo,  and  his 
Unters.  iiber  die  Bildung  der  Wizbellosen  Thiere  im  Eie. 


40  INSECT    TRANSFORMATIONS. 

to  the  wax  of  the  ears,  and  in  form  of  granules  which 
are  even  externally  apparent.* 

We  are  accustomed  to  consider  the  form  of  eggs  so 
nearly  regular,  that  the  epithet  c  egg-shaped'  is  fre- 
quently applied  to  other  things,  and  is  well  understood; 
but  the  eggs  of  insects,  though  most  commonly  round, 
are  seldom,  like  those  of  birds,  smaller  at  one  end 
than  at  the  other,  while  they  often  exhibit  forms  never 
seen  in  the  eggs  of  birds,  —  such  as  cylindric,  flat, 
depressed,  compressed,  prismatic,  angular,  square, 
boat-shaped^  &c.  These  varieties  of  form  are  just- 
ly referred  by  Kirby  and  Spence  to  the  c  manifold  wis- 
dom' (7roAo7ro<x/Ao;  ffo0**)J  ofthe  Creator;  but  we  have 
some  hesitation  in  admitting  their  limitation  of  this  to 
his  '  will  to  vary  forms,  and  so  to  glorify  his  wisdom, 
and  power  independently  of  other  considerations,'^ 
and  think  it  would  be  more  truly  philosophic  to  con- 
fess our  ignorance  where  we  cannot  explain  what  is 
above  our  comprehension.  Paley,  indeed,  says,  such 
facts  c  might  induce  us  to  believe  that  variety  itself, 
distinct  from  every  other  consideration,  was  a  motive 
in  the  mind  of  the  Creator,  or  with  the  agents  of  his 
will;'  but  he  immediately  adds,  '  to  this  great  variety 
in  organized  life  the  Deity  has  given,  or  perhaps  there 
arises  out  of  it,  a  corresponding  variety  of  animal  ap- 
petites, and  did  all  animals  covet  the  same  element, 
retreat,  or  food,  it  is  evident  how  much  fewer  could  be 
supplied  and  accommodated,  than  what  at  present  live 
conveniently  together,  and  find  a  plentiful  subsistence. '|| 
The  latter  remark,  we  think,  completely  destroys  the 
former,  and  it  will  lead  us  to  what  appears  to  be 

*  J.  R. 

t  Dumeril,  Consider.  G^ru rales,  p.  49;  and   Insect  Archi- 
tecture, p.  19. 

t  Ephes.  iii,  10.  §  Introd.  iii,  p.  95. 

H  Natural  Theology,  p.  345,  14th  ed. 


FORMS    OF    EGGS. 


41 


the  true  cause  of  the  varied  forms  of  the  eggs  of  in- 
sects. 


Eggs  of  a  butterfly  and  of  a  moth,  magnified. 

The  cause  of  the  eggs  of  birds  being  nearly  the 
same  in  shape,  arises,  we  should  say,  from  the  similar 
forms  of  the  animals  themselves;  while  insects  being 
much  more  varied  in  shape,  require  corresponding 
varieties  in  the  forms  of  their  eggs.  The  ostrich, 
the  eagle,  and  the  wren,  for  example,  differ  much 
more  in  size  than  in  their  general  form;  but  the 
earwig,  the  garden-spider,  butterflies,  beetles,  and 
grasshoppers,  differ  much  more  in  form  than  in  size, 
and  consequently  require  eggs  of  varying  forms  to 
contain  their  progeny.  We  confess,  however,  that 
we  cannot  always  trace  the  mathematical  causes  of 
these  diversities  of  form  in  the  eggs  of  insects;  for 
though  there  prevails  a  general  resemblance  in  those 
families  and  groups  the  most  nearly  allied,  yet  in 
others,  even  the  species  of  the  same  genus  exhibit 
differences  which  cannot  be  thus  accounted  for.  In 
two  species  of  Vanessa,  for  instance,  the  small  and 
the  great  tortoise-shell  butterflies,  which  differ  in 
little  but  size,  the  egg  of  the  small  is  cylindric  with 
eight  prominent  ribs,  while  that  of  the  great  is  shap- 
ed like  a  Florence  flask,  and  quite  smooth  and  uni- 
form.* 

The  ribbing  of  the  eggs  of  the  small  tortoise-shell 

*  Sepp,  der  Wonderen  Gods,  Tab.  ii,  and  viii. 
VOL.    vi.  4* 


42  INSECT    TRANSFORMATIONS. 

butterfly  (Vanessa  uiirc(R\  which  is  also  found  on 
those  of  most  of  the  species,  leads  us  to  remark  that 
insect  eggs  are  frequently  sculptured  in  a  very  beau- 
tiful manner,  far  out-rivalling  in  elegance  of  design 
and  delicacy  of  workmanship  the  engravings  which 
we  sometimes  see  on  eggs  brought  from  India  and 
China.  Some  of  them,  when  seen  through  a  micro- 
scope, remind  us  of  the  fine  crustaceous  shells  called 
sea-eggs,  —  a  resemblance  which  is  well  exemplified 
in  the  egg  of  the  angle-shades  moth  (Phlogopfiora 
meticulosa,  STEPHENS),  as  compared  with  the  Cly~ 
peaster  of  Parkinson. 


a,  magniiieu  egg  of  tlie  angle  shades  inutli  (  P/il<,ir<,  ,nura  mcti- 
cnlosa)  ;  6,  sca-egjr  (Clypcastcr,)  natural  size. 

These  channellings  appear  to  correspond  in  most 
cases  with  the  rings  of  the  caterpillar  to  be  hatched 
from  the  egg;  but  the  design  of  the  other  sculptures 
on  these  eggs  has  not  yet  been  discovered  by  the 
investigations  of  naturalists,  and  may.  probably,  for 
ever  elude  human  penetration.  But  though  we 
cannot  tell  why  an  insect's  egg  is  so  tastefully  carved, 
we  can  admire  the  minute  delicacy  and  extraordinary 
regularity  of  the  markings.  The  egg  of  the  meadow 
brown  butterfly  (Hipparchia  Jurlina)  is  crowned  at 
the  upper  end  with  sculptured  work  in  the  form  of 
tiles  or  slates,  as  if  to  defend  it  from  injury,  while 
others  are  covered  with  a  sort  of  net-work  of  extreme- 
ly minute  six-sided  meshes. 


FORMS    OF    EGGS.  43 


r,,  the  egg  ui  the  meadow  brown-butterfly,  magnified;  />,  egg 
of  the  biimstone-moth  (Rumia  Crata-gata),  magnified. 

The  design  of  the  appendages  to  some  sort  of 
eggs  is  much  more  apparent,  and  affords  us  some 
admirable  illustrations  of  prospective  contrivance. 
The  eggs  of  the  ephemerae,  for  example,  are  smooth 
and  oblong,  resembling  caraway  comfits,  a  form 
which  Swammerdam  proved  to  be  admirably  adapted 
for  diffusing  them  through  the  water,  where,  he  says, 
they  are  dropt  by  the  mother  insect.  For  this  pur- 
pose he  placed  '  a  few  of  them  on  the  point  of  a 
knife,  and  letting  them  fall  gently  into  water,  they 
immediately  separated  of  themselves  in  a  very  curious 
manner.'*  The  same  accurate  observer  describes  a 
very  remarkable  appendage  in  the  egg  of  the  water, 
scorpion  (Nepa  cinerea,  LINN.),  an  insect  by  no 
means  rare  in  Britain.  This  egg  is  furnished  with 
a  coronet  of  seven  bristles  disposed  like  the  down 
on  the  seed  of  the  blessed  thistle,  ( Centaurea 
benedicta,  WILLDENOW);  and  before  they  are  de- 
posited these  bristles  closely  embrace  the  egg  next 
to  them  in  the  ovary  like  a  sort  of  sheath,  as  if  a 
chain  of  thistle-seeds  were  formed,  by  placing  each 
successively  in  the  bosom  of  the  down  of  the  one 
next  to  it.  As  the  mother  insect  deposits  these  eggs 
in  the  stems  of  aquatic  plants,  the  bristles,  which  are 
partly  left  on  the  outside,  are  probably  intended  to 

*  Svvamm.  Book  of  Nature,  i,  104, 


44  INSECT   TRANSFORMATIONS. 

prevent  the  aperture  from  being  closed  up  by  the  ra 
pid  growth  of  the  plant. 

Reaumur  gives  an  interesting  description  of  a 
similar  egg  deposited  by  a  common  dung-fly,  of  a 
yellowish-orange  colour,  (Scatophaga  stercoraria, 
MEIGEN).  These  eggs  are  furnished  at  the  upper 
end  with  two  divergent  pegs,  which  prevent  them 
from  sinking  into  the  dung  where  they  are  placed  by 
the  parent,  while  they  are  permitted  to  enter  suffi- 
ciently far  to  preserve  them  moist.  Both  circum- 
stances are  indispensable  to  their  hatching;  for 
when  Reaumur  took  them  out  of  the  dung,  they 
shrivelled  up  in  a  few  hours,  and  when  he  immersed 
them  farther  than  the  two  pegs,  they  were  suffocated, 
and  could  not  afterwards  be  hatched.* 


«,  Dnng-fly  Scatophaga  Stercoraria)  ;  6  r,  front  and  side  views 
of  its  eggs-  magnified  ;  d  d  d,  a  number  of  these  eggs  deposited  in 
cow  dung. 

Before  we  began  to  study  the  habits  of  insects,  we 
found  upon  a  lilac-twig,  in  the  neighbourhood  of 
London,  a  singular  production,  which  we  took  for  a 
very  delicate  fungus,  and  supposing  it  not  to  be 
common,  we  carefully  preserved  the  specimens;  but 
we  have  since  learned,  with  no  little  surprise,  that 
these  are  the  eggs  of  the  lace-winged  fly,  (Chrysopa 
reticulata,  LEACH.)  Reaumur  says  that  several 
naturalists  have  described  them  as  fungi,  which  is 
not  to  be  wondered  at;  for  they  consist  of  a  small 
oval  greenish-white  head,  similar  to  the  apple-mould, 

*  Rraumur,  iv,  379. 


POSITION    OF    EGGS.  45 

with  a  white  transparent  stem,  more  than  an  inch 
high,  not  thicker  than  a  human  hair,  but  much  more 
stiff  and  rigid.  About  a  dozen  of  these  eggs  are 
deposited  in  a  single  and  sometimes  in  a  double  line, 
upon  the  leaves  and  branches  of  elder  or  other  trees 
and  plants  abounding  with  aphides,  upon  which  the 
grubs  feed  when  hatched.  The  footstalks  of  these 
eggs  are  formed  by  the  mother-fly  attaching  a  drop 
of  gluten  to  the  branch,  and  drawing  it  out  (as  a  spi- 
der does  its  line)  to  the  requisite  length  before  the  egg 
is  deposited  on  its  summit.  As  she  uses  her  body  for 
a  measure,  the  footstalks  are  by  consequence, all  near- 
ly of  equal  length.  It  is  evidently  the  design  of  these 
footstalks  to  place  the  eggs  out  of  the  reach  of  the 
grubs  of  lady-birds  (Coccinellce)  arid  of  aphidivorous 
•flies  (Syrphi),  which  frequent  the  same  situations  and 


Twig  of  lilac,  bearing  the  eggs  of  the  lace  winged  fly  (Ckrypscpa 
rtticulataj  Leach).    The  fly  is  seen  resting  on  the  lowest  leaf. 


46  INSECT    TRANSFORMATIONS. 

might  devour  them.  The  footstalks  are  so  smooth 
and  slender  that  these  grubs  could  not  climb  them,  as 
we  have  proved  by  experiment.* 

The  ichneumon  fly  (Ophion  luteum),  whose  larvae 
feed  upon  the  caterpillar  of  the  puss-moth,  also  de- 
posits eggs  with  a  footstalk;  and  what  is  most  singu- 
lar, these  larvaB,  after  they  are  hatched,  during  the 
first  stage  of  their  existence,  continue  attached  to  the 
shells  of  their  eggs.  It  is  not  till  the  puss  has  form- 
ed her  cocoon  that  they  devour  her,  and  spin  their 
own  cocoons  under  its  cover,  j* 

The  eggs  of  insects  do  not  seem  to  hold  any  regu- 
lar proportion,  so  far  as  regards  size,  with  their  parent 
insects;  for  some  large  moths  lay  very  small  eggs, 
while  others  of  a  small  size  lay  eggs  considerably  lar- 
ger. Kirby  and  Spence  think  it  probable  that  eggs' 
which  produce  females  are  generally  larger  than  male 
eggs;  with  the  exception  of  the  hive-bee,  in  which 
the  reverse  takes  place.  Huber,  as  we  have  seen 
above,  found  the  eggs  of  ants  of  different  sizes,  from 
which  he  was  led  to  discover  that  they  increase  in  size 
after  being  deposited. 

It  has  been  remarked,  that  animals  of  prey  are  less 
prolific  than  those  which  live  on  vegetable  food;  and 
a  similar  principle  appears  to  hold  to  a  certain  extent 
amongst  insects,  the  most  prolific  families  belonging, 
with  few  exceptions,  to  those  which  devour  vegeta- 
ble or  animal  substances  beginning  to  decay  and 
putrefy. 

Thus  it  is  that  the  eagle  lays  only  two  eggs,  while 
the  wren  lays  eight,  and  the  pheasant  twenty-four  ; 
and  in  the  same  way  the  dragon-flies  (Libellulina, 
MAC  LEAY),  do  not  lay  above  two  dozen  eggs,  the 
lace- winged  flies  (Hemerobidce)  still  fewer,  and  the 
noontide  fly  (Mesembrina  meridiana,  ME i GEN)  only 

*  J.  R.         t  See  Insect  Architecture,  pp.  195  —  325,  6. 


FECUNDITY   OF    INSECTS   AND    FISHES.  47 

deposits  two  eggs;  while  a  single  plant-louse  (Aphis), 
as  we  mentioned  before  from  Reaumur,  may  be  the 
living  progenitor  of  5,904,900,000  descendants,  and 
the  queen  of  the  warrior  white  ants  ( Termes  bellico- 
susj  SMEATHM.),  produces  31,536,000  eggs  in  one 
year. 

We  may  illustrate  this  subject  by  an  extract  exem- 
plifying the  proportionate  fecundity  of  the  animal  king- 
dom in  general.  c  Compared  with  the  rest  of  ani- 
mated nature,'  says  Daly  ell,  c  infusion  animalcula  are 
surely  the  most  numerous:  next  are  worms,  insects, 
or  fishes;  amphibia  and  serpents,  birds,  quadrupeds; 
and  last  is  man.  The  human  female  produces  only 
one  at  a  time,  that  after  a  considerable  interval  from 
birth,  and  but  few  during  her  whole  existence.  Many 
quadrupeds  are  subject  to  similar  laws;  some  are 
more  fertile,  and  their  fecundity  is  little,  if  at  all,  in- 
ferior to  that  of  certain  birds,  for  they  will  produce 
ten  or  twenty  at  once.  Several  birds  will  breed  fre- 
quently in  a  year,  and  have  more  than  a  single  egg 
at  a  time.  How  prodigious  is  the  difference,  on  de- 
scending to  fishes,  amphibia,  reptiles,  insects,  and 
worms!  Yet  among  them  the  numbers  cannot  be 
more  different.  According  to  naturalists,  a  scorpion 
will  produce  sixty-five  young;  a  common  fly  will  lay 
144  eggs;  a  leech,  150;  and  a  spider,  170.  I  have 
seen  a  hydrachna  produce  600  eggs,  and  a  female 
moth  1 100.  A  tortoise,  it  is  said,  will  lay  1000  eggs, 
and  a  frog  1 100.  A  gall  insect  has  laid  5000  eggs; 
a  shrimp,  6000;  and  10,000  have  been  found  in  the 
ovary,  or  what  is  supposed  to  be  that  part,  of  an  as- 
carides.  One  naturalist  found  above  12,000  eggs 
in  a  lobster,  and  another  above  21,000.  An  insect 
very  similar  to  an  ant  (Mulillal)  has  produced  80,000 
in  a  single  day ;  and  Leeuwenhoeck  seems  to  compute 
four  millions  in  a  crab.  Many  fishes,  and  those 
which  in  some  countries  seldom  occur,  produce  in- 


48  INSECT    TRANSFORMATIONS. 

credible  numbers  of  eggs.  Above  36,000  have  been 
counted  in  a  herring;  38,000  in  a  smelt;  1,000,000 
in  a  sole;  1,130,000  in  a  roach;  3,000,000  in  a  spe- 
cies of  sturgeon;  342,000  in  a  carp;  383,000  in  a 
tench;  546,000  in  a  mackerel;  99:2,000  in  a  perch; 
and  1 ,357,000  in  a  flounder.  But  of  all  fishes  hither- 
to discovered,  the  cod  seems  the  most  fertile.  One 
naturalist  computes  that  it  produces  more  than 
3,686,000  eggs;  another  9,000,000;  and  a  third 
9,444,000.  Here,  then,  are  eleven  fishes,  which 
probably,  in  the  course  of  one  season,  will  produce 
above  thirteen  millions  of  eggs;  which  is  a  number  so 
astonishing  and  immense,  that,  without  demonstration, 
we  could  never  believe  it  true.'* 

The  fecundity  of  insects  is  no  less  remarkable  than 
that  of  fishes.  In  some  instances,  particularly  in  those 
already  mentioned,  the  numbers  produced  from  the 
eggs  of  a  single  female,  far  exceed  the  progeny  of  any 
other  class  of  animals.  It  is  this  extraordinary  fecun- 
dity which,  under  favourable  circumstances,  produces 
countless  swarms  of  insects  that  give  origin  to  the 
opinion  of  their  being  spontaneously  generated  by 
putrefaction,  or  brought  in  some  mysterious  way  by 
blighting  winds.  The  numerous  accidents,  however, 
to  which  insects  are  exposed  from  the  deposition  of 
the  egg  till  their  final  transformation,  tend  to  keep  their 
numbers  from  becoming  excessive,  or  to  reduce  them 
when  they  are  at  any  time  more  than  commonly  nume- 
rous. 

*  Introd.  Observ.  to  Spallanzani,  xiv. 


CHAPTER   III. 

Maternal  Care  of  Insects  in  depositing  their  Eggs.  —  Solitary  Bees. — 
Wasps.  —  Ichneumons.  —  Moths.  —  Butterflies.  —  Gnats.  —  Mistakes 
of  Instinct. 

LORD  KAIMES,  in  his  '  Gentleman  Farmer,'  men- 
tions the  singular  fact  that  the  female  sheep,  weeks 
before  yeaning,  selects  some  sheltered  spot  where 
she  may  drop  her  lamb  with  the  most  comfort  and 
security;  and  when  forcibly  prevented  from  going 
there,  she  manifests  the  utmost  uneasiness.  But 
this  instance  of  prospectively  providing  for  a  future 
progeny  is  exemplified  much  more  strikingly  in  most 
insects,  in  consequence  of  the  great  difference  of 
their  economy  compared  with  that  of  other  animals. 
The  sheep  and  other  mammalian  quadrupeds  suckle 
their  young,  and  watch  over  them  with  the  most 
affectionate  care  during  the  earlier  and  more  help- 
less stage  of  their  existence.  This,  on  the  contrary, 
is  only  found  in  a  few  cases  among  insects,  such  as 
the  social  bees,  wasps,  and  ants;  for  the  greater 
number  of  species  never  live  to  see  their  descend- 
ants. The  numerous  families,  indeed,  of  moths, 
butterflies,  and  other  winged  insects,  seldom  live 
more  than  a  few  days  after  they  have  deposited 
their  eggs,  though  some  other  species  probably  live 
many  months.  The  latter,  however,  are  only  ex- 
ceptions to  the  general  rule,  that  insects,  after  depo*- 
siting  their  eggs,  very  soon  die.  The  wisdom  of 
Providence,  therefore,  has  endowed  female  insects 
with  the  most  wonderful  acuteness  and  skill  in  anti- 
cipating the  wants  of  their  young,  when  they  escape 

VOL.  vi.  5 


50  INSECT    TRANSFORMATIONS. 

from  the  egg,  and  have  no  mother  to  direct  or  pro- 
vide for  them. 

We  have  numerous  beautiful  instances  of  this  in 
the  solitary  bees  and  wasps,  which  perform  indefa- 
tigable labours  in  hewing  out  nests  in  wood  and  stone, 
and  building  structures  of  clay,  leaves,  cotton,  and 
other  materials,  as  we  have  elsewhere  detailed  at 
length.*  But  we  recently  met  with  an  example  of 
this,  which  we  shall  briefly  notice.  A  small  solitary 
bee,  (Chelostoma  florisomne?)  not  so  large  as  the 
domestic  fly,  and  more  slender  in  the  body,  instead 
of  digging  into  the  ground  like  its  congeners,!  bores 
a  hole  in  a  tree  about  the  diameter  of  a  wheat  straw, 
and,  when  empty,  resembling  externally  the  timber 
holes  of  the  furniture  beetle  (Jlnobium  pertinax)  for 
which,  indeed,  we  at  first  mistook  them,  till  we  were 
undeceived  by  seeing  the  little  bees  going  in  and  out. 
When  the  work  is  completed,  however,  the  hole  can 
only  be  detected  by  a  practised  eye,  for  it  is  neatly 
covered  with  a  substance,  the  nature  of  which  remains 
to  be  discovered.  It  is  a  gray  semi-transparent 
membrane,  somewhat  resembling  the  slime  of  a  snail 
when  dried;  but  whether  it  is  secreted  by  the  bee 
like  wax,  or  gathered  from  plants  like  propolis,  we 
cannot  tell.  As  we  had  a  whole  colony  of  these  little 
wood-boring  bees  in  the  stump  of  a  growing  poplar 
at  Lee,  we  cut  out  several  of  the  perforations,  in 
order  to  examine  the  interior.  These  we  found  more 
than  an  inch  deep,  and  filled  to  the  brim  with  a  thin 
whitish  honey;  but,  like  those  of  the  larger  carpenter 
bees  of  a  different  genus  (Xylocopa),  they  were  divi- 
ded by  several  partitions  of  the  same  membranous  ma- 
terial. 

The  circumstance,  however,  which  induces  us  to 
give  these  details  here,  relates  to  the  eggs  deposited 

*  See  Insect  Architecture,  pp.  24 —  64,  &c.         t  Ibid,  p.  43. 


EGGS    OF    THE    SOLITARY   BEE.  51 

in  these  singular  perforations.  It  is  obvious,  if  the 
eggs  were  laid  in  the  midst  of  the  liquid  honey,  that 
they  would  either  be  prevented  from  hatching,  or  the 
grub  would  be  suffocated  in  the  first  stage  of  its  exist- 
ence. Every  chamber  of  the  little  nest  is  so  full  of 
honey,  that  it  is  difficult  to  divine  how  this  is  to  be 
avoided,  and  it  was  only  after  repeated  and  anxious  re- 
searches that  we  found  a  solution  of  the  difficulty.  It 
is  this:  the  mother-bee,  when  she  has  filled  a  chamber 
with  honey,  glues  a  single  egg,  a  hair's  breadth  or  two 
above  its  surface,  and  at  a  similar  minute  distance  she 
stretches  the  membranous  partition,  leaving  between 
this  and  the  surface  of  the  honey  just  sufficient  space, 
and  no  more,  for  the  newly  hatched  grub  to  crawl  all 
round.  On  opening  one  of  these  perforations  after 
the  grub  had  been  some  time  hatched,  we  found  it 
keeping  aloof  from  the  honey,  and  resting  on  the 
upper  margin,  from  which  it  seemed  to  have  stretch- 
ed its  head  when  feeding  to  the  centre,  instead  of 
eating  at  the  circumference.  The  honey  was  also 
then  become  thicker  in  consistence,  and,  in  conse- 
quence of  what  had  been  consumed,  formed  a  hollow 
cup.* 

Reaumur  describes  the  nest  of  a  bee  of  the 
same  family  (Jlndrena  cineraria,  FABR.),  which  is 
found  in  the  neighbourhood  of  London,  and  differs 
from  the  preceding  in  making  perforations,  not  in 
trees,  but  in  the  ground,  and  lining  these  with  the 
membranaceous  substance  that  composes  the  parti- 
tions and  the  outer  covering.  He  takes  no  notice, 
however,  of  the  prospective  ingenuity  with  which 
the  egg  is  placed  above  the  surface  of  the  fluid 
honey. | 

The  various  species  of  nests  thus  prepared  by  the 
parent  insects  for  depositing  their  eggs,  are  not 
merely  intended  for  holding  provisions  and  shel- 

*  J.  R.  t  Reaumur,  Mem.,  vol.  vi,  p.  131. 


52  INSECT    TRANSFORMATIONS. 

tering  the  young  grub  from  the  inclemencies  of  the 
weather,  or  from  being  preyed  upon  by  birds.  There 
are  more  insidious  and  no  less  destructive  enemies 
than  these  to  guard  against.  This  we  shall  imme- 
diately show  from  the  economy  of  other  families  of 
the  same  order,  whose  proceedings  also  strictly 
illustrate  the  subject  of  maternal  care.  In  popular 
works  on  natural  history  the  insects  alluded  to  are 
indiscriminately  called  Ichneumons,  a  name  signifying 
PryerSj  and  first  given  by  Aristotle  to  wasps.  But 
recently  this  term  has  been  considerably  restricted, 
and  therefore  does  not  properly  apply  to  many 
insects  whose  economy  resembles  the  true  ichneu- 
mons. It  is  the  practice,  then,  of  a  very  great  num- 
ber of  insects,  of  different  orders  and  families,  to  take 
advantage  of  the  labours  of  other  insects  in  pro- 
viding for  their  progeny,  in  the  same  way  as  the 
common  cuckoo  and  the  cow-bunting  of  America 
(Emberiza  pecoris,  WILSON)  lay  their  eggs  in  the 
nests  of  other  birds.  The  venerable  Dr  Jenner  was 
the  first  to  publish,*  what  had  long  been  known  to 
our  peasants,  that  the  young  cuckoo,  when  hatched, 
soon  ejects  from  the  nest  into  which  it  has  been 
surreptitiously  introduced  the  eggs  or  young  of  its 
foster  parent;  but  the  insects  under  notice  act  still 
more  ungratefully.  They  do  not,  indeed,  live  upon 
the  honey  or  other  provision  stored  up  by  the 
builder  of  the  nest  for  the  use  of  her  own  young, 
since,  being  all  carnivorous,  this  is  not  to  their  taste; 
but  they  permit  the  rightful  owner  of  the  food  to 
feast  and  fatten  on  it,  that  they  may  make  of  him  a 
more  substantial  repast.  The  great  numbers  of  dif- 
ferent species  of  insects  which  are  reared  in  this  sin- 
gular manner  would  appear  almost  incredible  to  one 
who  had  not  studied  their  economy;  but  it  cannot 
fail  to  meet  the  young  entomologist  at  the  very 

*  Phil.  Trans,  for  1788,  p.  219. 


PRECAUTIONS    OP    INSECTS.  53 

outset  of  his  studies;  for  it  is  scarcely  possible  for  many 
broods  of  insects  to  be  reared  without  observing  it. 

The  insidious  proceedings  of  these  cuckoo  insects, 
as  we  may  not  inappropriately  call  them,  give  rise  to 
remarkable  displays  of  ingenuity  on  the  part  of  the 
mothers  whose  progeny  is  exposed  to  their  felonious 
designs.  It  is  the  usual  practice  of  the  solitary  bees 
and  wasps  to  leave  the  whole  task  of  constructing  and 
provisioning  the  nest  to  the  female,  the  male,  like  an 
American  Indian,  taking  no  part  in  those  domestic 
concerns.  In  this  case,  though  she  is  seldom  absent 
from  the  spot  for  more  than  two  or  three  minutes  at  a 
time,  some  prying  Chrysis  or  Tachina  often  glides 
into  her  domicil,  and  finds  time  to  deposit  its  egg 
and  to  escape  before  her  return.  Other  solitary  bees 
exhibit  both  more  civilization  and  more  cunning;  for 
the  male  assists,  at  least,  in  watching  and  guarding 
the  nest,  if  he  does  not  lend  a  hand  in  its  construc- 
tion. The  proceedings  of  one  of  these  solitary  bees 
(Halictus  fulvocinctusy  STEPH.),  indigenous  in  the 
vicinity  of  London,  has  frequently  fallen  under  our 
observation.  It  constructs  a  gallery,  having  on  the 
outside  only  a  single  perpendicular  passage,  but  bran- 
ching out  into  seven  or  eight,  at  the  bottom  of  each 
of  which  is  placed  a  globule  of  pollen  kneaded  up  with 
honey  about  the  size  of  a  pea,  where  an  egg  is  depos- 
ited. Walckeria'er,  who  observed  these  insects  with 
great  care,  remarks,  that  they  only  work  during  the 
night  in  making  their  galleries;  and  our  observations 
so  far  agree  with  his,  that  though  we  have  observed 
some  dozens  of  their  nests,  we  never  saw  them  at 
work  in  the  day.  Instead  of  this,  either  the  male  or 
the  female  always  remains  at  the  entrance  of  the  nest 
(which  its  head  exactly  fills)  ready  to  give  no  friendly 
reception  to  any  enemy  that  may  venture  to  intrude. 
We  have  otten  seen,  indeed,  the  ruby-tail  fly  (Chrysis 

VOL.  vi.  5* 


54  INSECT    TRANSFORMATIONS. 

ignita),  on  approaching  this  vigilant  sentinel,  fly  off 
in  all  haste,  with  evident  fear  of  the  consequences. 
But,  as  Walckenaer  justly  remarks,  should  the  part- 
ner of  its  cares  return  from  a  foraging  excursion,  and 
take  two  or  three  circular  flights  around  the  entrance 
to  announce  its  arrival,  the  sentinel  bee  immediately 
makes  way  by  withdrawing  into  the  interior.  Should 
the  sentinel  bee  be  absent  through  any  cause  from 
its  post,  and  the  forager  enter  without  announcing 
its  arrival,  it  is  immediately  driven  back  and  pu- 
nished for  so  unpardonable  a  breach  of  etiquette.* 

Another  circumstance  worthy  of  notice  in  the 
manners  of  these  bees  (Halicti)  is,  that  they  fly 
directly  into  the  entrance  of  their  nests  without  ever 
alighting  upon  any  contiguous  object,  a  circum- 
stance which  is  attributed  by  Walckenaer  to  their 
fear  of  enemies,  numbers  of  which  are  always  lurk- 
ing about  with  evil  intent.  More  than  one  species 
of  spider  and  several  sorts  of  wasps  lie  in  wait  to 
make  prey  of  them,  besides  those  we  have  men- 
tioned as  being  on  the  alert  to  introduce  their  eggs 
into  their  nest.  But  their  most  formidable  enemy  is 
a  solitary  wasp  (Cerceris  ornatci),  numbers  of 
which  make  their  nests  in  the  very  midst  of  their 
colonies.  The  wasps  surround  the  interior  margin 
of  their  holes  with  a  rampart  of  sand,  agglutinated 
with  a  whitish  mortar,  and  well  polished.  The  gal- 
lery is  five  inches  deep,  somewhat  in  the  form  of  an 
S,  in  which  the  female  lays  her  eggs,  with  a  store  of 
provisions  for  her  future  young,  consisting  of  the 
living  bodies  of  her  bee  neighbours,  the  poor  Halicti. 
It  is  only  on  fine  days,  between  eleven  and  four 
o'clock,  that  the  mother  wasp  engages  in  the  chase 
of  the  bees,  and  may  be  seen  flying  with  the  most 
lively  ardour  around  their  nests.  When  an  unfortu- 

*  Walck.  Mem.  des  Abeilles  Solit.     Paris,  1817. 


INSECTS    OF    PREY.  55 

nate  bee  ventures  at  this  time  to  approach  its  home, 
the  wasp  pounces  upon  it  as  a  .hawk  would  pounce 
upon  a  sparrow,  seizes  it  by  the  back  of  the  neck, 
carries  it  to  the  ground,  and  placing  it  by  the  side  of 
a  small  stone  or  clod  of  earth,  she  turns  it  round  upon 
its  back.  Then  standing  upon  its  belly  in  an  attitude 
of  conscious  triumph,  she  darts  her  sting  into  the 
lower  part  of  its  head,  in  such  a  manner  as  to  stupify 
it,  but  not  to  kill  outright.  As  soon  as  she  has  in 
this  manner  laid  in  a  sufficient  store  of  half-dead 
bees,  she  closes  up  the  entrance.* 

Several  species  of  this  family  of  wasps  (Cerceris 
aurita,  LATH.,  and  C.  quadrifasciata,  Bosc)  are 
of  essential  service  to  agriculturists  by  provisioning 
their  nests  with  destructive  weevils  (Curculionidce), 
so  injurious  to  orchards  and  nurseries.")"  Other 
families  of  this  order  in  a  similar  way  provide  for 
their  progeny  a  supply  of  living  insects  of  different 
species,  of  which  interesting  accounts  have  been 
given  by  more  than  one  naturalist. J 

The  insects,  however,  of  these  marauding  tribes 
are  not  permitted  to  carry  on  their  depredations  on 
their  more  peaceful  neighbours  with  impunity;  for 
nature  has  provided  other  races  of  animals  to  make 
prey  of  them.  We  do  not  allude  merely  to  birds 
and  reptiles,  which  devour  as  many  of  those  carni- 
vorous wasps  as  they  can  catch ;  for  there  is  also  a 
numerous  tribe  of  insects  who  have  the  address  to 
foil  them  at  their  own  weapons.  All  the  careful 
stratagems  of  the  mason  wasp  ( Odynerus  murarius, 
LATR.),  in  rearing  her  turretted  outworks  to  defend 
her  premises  while  she  excavates  her  galleries,^ 
often  prove  ineffectual  in  guarding  against  the  insi- 

*  Walck. ;  Latreille,    Annales  du  Museum,  torn,  xiv;  and 
Bosc,  Ann.  de  1'Agric,  vol.  liii. 
t  Bosc,  Ann.  de  1'Agric.,  vol.  liii. 
£  See  Insect  Architecture,  pp.  26-33.     $  Ibid,  pp.  30  -  32. 


56  INSECT   TRANSFORMATIONS. 

dious  intrusion  of  a  common  ichneumon  fly  (Pimpla 
manifestator,  GRAVENHORST),  easily  known  by  its 
being  black,  with  the  legs  red.  This  ichneumon 
sometimes  pays  a  visit  to  the  nest  of  the  wasp  before  it 
is  completed,  for  Reaumur  has  seen  one  peep  into  the 
entrance  and  then  start  back  as  if  afraid  of  its 
depth;  but,  for  the  most  part,  she  waits  patiently  till 
the  wasp,  having  laid  in  a  store  of  caterpillars  for 
the  young  one,  closes  up  the  doorway  with  a  bar- 
ricade of  kneaded  clay.  It  is  this  very  barricade 
which  the  ichneumon  determines  to  assail  in  order  to 
find  a  nest  ready  prepared  and  stocked  with  provi- 
sions for  her  own  progeny.  With  this  design  she 
makes  use  of  her  ovipositor,  which  is  as  admirably 
adapted  to  the  purpose  of  those  as  the  saw-flies  or 
the  tree-hoppers  (Cicadce.) 

The  ovipositor  of  all  the  true  ichneumons  (Ich- 
neumonidce)  is  similarly  constructed,  consisting  of  a 
borer  enclosed  in  a  sheath,  which  opens  ^through  its 
whole  length  like  the  legs  of  a  pair  of  compasses.  It 
is  longer  or  shorter,  and  stronger  or  more  slender, 
according  to  the  substances  which  it  may  be  neces- 
sary to  penetrate  when  the  eggs  are  deposited.  The 
description,  therefore,  of  the  ovipositor  of  the  one 
just  alluded  to  (P.  manifestator)  will  be  sufficient  to 
give  the  reader  a  distinct  notion  of  the  others 
Being  intended  to  penetrate  into  the  deep  holes  dug 
by  mason  wasps,  the  ovipositor  of  this  insect  is 
nearly  three  inches  long,  and,  as  it  is  not  concealed 
in  the  body  like  those  of  gall  flies,  it  appears  like  a 
tail  formed  of  a  long  black  bristle.  On  examining 
this  a  little  more  narrowly,  we  find  that  what 
appears  to  be  a  single  bristle  is  in  reality  three,  two 
side  ones  forming  a  sheath,  and  the  middle  one  a 
borer  or  brad-awl  for  piercing  the  clay  barricado  of 
the  mason  wasp's  nest.  The  termination  of  the 
borer  is  not,  however,  smooth,  like  that  of  a  brad- 


ICHNEUMONS. 


57 


awl,  but  toothed  like  a  saw,  only  the  teeth,  seven  or 
eight,  are  not  oblique,  but  perpendicular,  a  structure 
better  fitted  for  acting  upon  clay,  as  the  teeth  will 
not  become  so  readily  clogged,  and  the  instrument 
will  be  more  easily  retracted.  The  figures  will  make 
this  more  perspicuous  than  the  best  description. 


«,  the  Pimpla  manifcstator ;  6,  its  ovipositor  opened  outwards ; 
c  c  c  e,  magnified  view  of  its  ovipositor  ;  rf,  the  toothed  point  of  the 
borer. 

In  order  to  study  the  economy  of  the  mason  wasps 
(Odyneri)  more  effectually,  Reaumur  made  an  arti- 
ficial vespiary  of  sand  and  mortar  upon  a  wall,  which 
at  the  same  time  gave  him  an  excellent  opportunity 
of  observing  the  manoeuvres  of  the  ichneumons.  *  I 
perceived,'  he  tells  us,  4  one  of  these  ichneumons, 
at  the  instant  it  alighted  on  the  spot  under  which 
so  many  of  the  little  green  caterpillars  had  been 
stored  up  by  the  wasps.  Its  long  tail,  which  it 
carried  horizontally,  appeared  to  form  but  one  bristle, 
though  it  was  really  composed  of  three;  and  though 
it  carried  it  on  a  line  with  its  body,  it  soon  showed 
me  that  it  was  capable  both  of  raising  and  lowering 
it,  as  well  as  of  bending  it  in  various  directions, 
and  in  different  proportions  to  its  length.  It  moved 
its  ovipositor  so  as  to  bring  it  into  a  bent  position 
under  its  body,  protruding  it  even  beyond  its  own 
head;  taking  care  to  direct  it  into  the  barricadoed 


58 


INSECT   TRANSFORMATIONS. 


nest  of  the  mason  wasp.  But  although  the  insect 
appeared  not  to  be  disturbed  by  my  observations,  yet 
1  was  unable  to  perceive  whether  the  toothed  portion 
of  the  borer  was  pushed  beyond  the  sides  of  the  sheath. 
What  I  did  see,  however,  convinced  me  that  the  in- 
strument was  worked  in  a  manner  well  adapted  to 
make  its  way  through  the  mortar;  for  she  turned  it 
half  round  alternately  from  right  to  left  and  from  left 
to  right,  as  a  carpenter  would  his  brad-awl,  and 
employed  altogether  more  than  a  quarter  of  an  hour 
before  she  succeeded  in  penetrating  to  a  sufficient 
depth.'* 


Ichneumon  flies  ovipositing,  a  a,  an  ichneumon  fly.  &  6,  its 
ovipositor,  c,  an  ichneumon,  which  has  just  bored  through  the 
closed  substance  of  a  sand  wasp's  nest  at  < ,  into  which  her  ovi- 
positor, d,  descends  to  the  coil  of  caterpillars  at/,  where  the 
egg  is  laid. 

t  Reaumur,  Mem.  vi,  p.  304. 


PARASITE    EGGS.  59 

Another  parasite  (Pimpla  strobikllce,  FABR.)  is 
armed  with  a  long  ovipositor,  with  which  it  deposits 
its  eggs  in  larvae,  that  burrow  in  the  fruit-cones  of 
the  fir. 

The  intrusion  of  these  parasite  eggs  into  the  nests 
of  insects  is  often  an  exceedingly  puzzling  circum- 
stance to  naturalists,  in  their  earlier  researches;  and 
sometimes  even  deceives  those  of  considerable  expe- 
rience and  acuteness  into  the  supposition  that  the 
insects  ultimately  produced  are  in  reality  those  of 
the  original  builder  of  the  nest.  These  deceptions 
frequently  occur  in  the  numerous  species  of  vege- 
table galls,  originating  chiefly  in  the  economy  of  a 
beautiful  family  of  insects  (Chalcididce,  WEST  WOOD). 
When  the  gall-fly  (  Cynips)  has  deposited  its  eggs  on 
the  bud  or  the  leaf  of  a  plant  in  such  a  manner  as  to 
insure  their  being  surrounded  with  a  thick  coating  of 
vegetable  substance,  they  are  not  on  that  account  se- 
cure from  the  insects  just  alluded  to;  for  the  Chalets, 
armed  by  nature  with  an  instrument  for  the  purpose, 
can  penetrate  in  any  direction  the  largest  oak-apple 
or  bedeguar  of  the  rose.*  The  most  obvious  distinc- 
tion between  these  parasites  and  the  true  gall-flies,  is, 
that  in  the  latter  the  ovipositor  is  partly  concealed, 
while  in  the  former  it  is  altogether  external,  like  the 
ichneumons  in  the  preceding  figure  ;  but  this  dis- 
tinction is  of  course  wanting  in  the  male  insects.  It 
was  the  observation  of  different  species  of  insects, 
produced  in  this  manner  from  the  same  sort  of  gall, 
which  betrayed  the  illustrious  Redi  into  the  fanciful 
notion  of  their  being  generated  by  a  vegetative  and 
sensitive  soul  in  the  plant  itself,  to  which  also  he  attri- 
buted the  generation  of  the  grubs  found  in  nuts,  cher- 
ries, and  other  fruits.  '  There  is  nothing,'  as  Reau- 
mur justly  remarks,  cmore  fitted  to  humiliate  the  best 
reasoners,  and  to  inspire  them  with  a  well-founded 

*  See  Insect  Architecture,  pp.  375  —  384. 


60  INSECT    TRANSFORMATIONS. 

distrust  of  novel  opinions,  than  to  see  a  man  like  Redi, 
who  had  declared  open  war  against  popular  prejudices, 
and  successfully  combated  many  of  them,  thus  adopt- 
ing a  notion  so  improbable,  or  (to  use  a  stronger  term) 
so  pitiable.'*  It  was  Redi's  countryman,  Malpighi, 
who  first  discovered  the  genuine  history  of  gall-flies; 
but  when  we  consider  that  from  the  bedeguar  gall  of 
the  rose  alone  no  less  than  three  different  species  of 
insects  may  proceed,  two  of  which  (Callimone  bede- 
guaris,  and  Eurytoma  stigma,  STEPHENS)  are  para- 
sites, Redi  had  some  cause  for  being  puzzled  to  ex- 
plain the  phenomena. 

Two  other  distinguished  naturalists,  Goedart  and 
Ray,  found  no  less  difficulty  in  accounting  for  the 
progeny  of  ichneumons  issuing  from  the  caterpillars 
and  chrysalides  of  butterflies.  Ray,  indeed,  lived  to 
ascertain  the  fact;  but  he  was  at  one  time  inclined  to 
believe,  with  Goedart,  that  when,  from  any  defect 
or  weakness,  Nature  could  not  bring  a  caterpillar  to 
a  butterfly,  in  order  that  her  aim  might  not  be  en- 
tirely defeated,  she  stopped  short,  and  formed  them 
into  insects  of  a  smaller  size,  and  less  "perfect  struc- 
ture.f  M.  Goedart  even  persuaded  himself,  says 
Rc-aumur  sarcastically,  that  he  had  observed  the  ca- 
terpillar interesting  itself  for  its  infant  progeny,  by 
weaving  for  them  an  envelope  of  silk.  It  was  also 
fancied  that  what  was  wanting  in  size  in  the  parasite 
flies,  when  compared  with  the  expected  butterfly  j  was 
made  up  in  their  greater  numbers  ;J  with  as  much 
probability,  says  Reaumur,  as  that  a  cat  would  kitten 
a  number  of  mice.  The  simple  facts  which  we  shall 
now  state,  will  point  out  the  origin  of  these  strange 
mistakes. 

*  Reaumur,  Mem.  iii,  p.  476. 

t  Ray,  Hist.  Ins.,Pref.  xv,  and  Cant.  137. 

j  Goedart,  quoted  by  Rcaumur,  vol.  ii,  p.  415. 


PARASITE    INSECTS.  61 

It  must  have  occurred  to  the  least  attentive  obser- 
vers of  the  very  common  cabbage  caterpillar  (Pontia 
Brassicce),  that  when  it  ceases  to  feed,  and  leaves  its 
native  cabbage  to  creep  up  walls  and  palings,  it  is 
often  transformed  into  a  group  of  little  balls  of  silk, 
of  a  fine  texture  and  a  beautiful  canary  yellow  colour; 
from  each  of  which  there  issues,  in  process  of  time,  a 
small  four-winged  fly  (Microgaster  glomeratus,  SPI- 
JNOLA),  of  a  black  colour,  except  the  legs,  which  are 
yellow.  By  breeding  these  flies  in  a  state  of  confine- 
ment, and  introducing  them  to  some  cabbage  caterpil- 
lars, their  proceedings  in  depositing  their  eggs  may  be 
observed.  We  have  more  than  once  seen  one  of  these 
little  flies  select  a  caterpillar,  and  perch  upon  its  back, 
holding  her  ovipositor  ready  brandished  to  plunge  be- 
tween the  rings  which  she  seems  to  prefer.  When 
she  has  thus  begun  laying  her  eggs,  she  does  not  rea- 
dily take  alarm;  but,  as  Reaumur  justly  remarks,  will 
permit  an  observer  to  approach  her  with  a  magnifying 
glass  of  a  very  short  focus.  Having  deposited  one 
egg,  she  withdraws  her  ovipositor,  and  again  plunges 
it  with  another  egg  into  a  different  part  of  the  body  of 
the  caterpillar,  till  she  has  laid  in  all  about  thirty  eggs. 
It  is  not  a  little  remarkable,  that  the  poor  caterpillar, 
whose  body  is  thus  pierced  with  so  many  wounds,  seems 
to  bear  it  very  patiently,  and  does  not  turn  upon  the 
fly,  as  he  would  be  certain  to  do  upon  another  cater- 
pillar should  it  venture  to  pinch  him;  a  circumstance 
by  no  means  unusual.  Sometimes,  indeed,  he  gives 
a  slight  jerk,  but  the  fly  does  not  appear  to  be  at  all 
incommoded  by  the  intimation  that  her  presence  is  dis- 
agreeable. 

The  eggs,  it  may  be  remarked,  are  thrust  suffi- 
ciently deep  to  prevent  their  being  thrown  off  when 
the  caterpillar  casts  its  skin;  and,  being  in  due  time 
hatched,  th4pgnibs  feed  in  concert  on  the  living 
body  of  the  caterpillar.  The  most  wonderful  circum- 

VOL.   vi.  6 


62  INSECT    TRANSFORMATIONS. 

stance,  indeed,  of  the  whole  phenomenon,  is  the  in- 
stinct with  which  the  grubs  are  evidently  guided  to 
avoid  devouring  any  vital  part,  so  that  they  may  not 
kill  the  caterpillar,  as  in  that  case  it  would  be  useless 
to  them  for  food.  When  full  grown,  they  even  eat 
their  way  through  the  skin  of  the  caterpillar  without 
killing  it;  though  it  generally  dies  in  a  few  days  with- 
out moving  far  from  the  place  where  the  grubs  have 
spun  their  group  of  silken  cocoons  in  which  to  pass  the 
winter. 


Generation  of  Ichneumons.  «  a,  the  caterpillar  a^^ontia  Brassier. 
6,  the  eggs  of  that  butterfly  glued  to  a  leaf,  c,  Mid^Juster  glomeratus, 
magnified,  d  d  d,  a  magnified  view  of  a  dissected  caterpillar,  in  whose 
body  a  number  of  ichneumon  caterpillars  have  been  hatched,  e,  silk  co- 
coons spun  by  the  ichneumons.  /,  grabs  spinning  cocoons.  £-,  grub* 
eating  their  way  out  of  the  caterpillar. 


PARASITE    INSECTS.  63 

But  it  is  not  only  in  the  nests  of  bees  and  wasps,  or 
in  the  bodies  of  caterpillars,  that  these  provident  mo- 
thers contrive  to  deposit  their  eggs;  for  many  of  them 
are  so  very  minute,  as  to  find  in  the  eggs  themselves 
of  larger  insects  a  sufficient  magazine  of  food  for  their 
progeny ;  and  accordingly,  piercing  the  shell  with  their 
ovipositor,  they  thrust  their  own  into  the  perforation. 
The  most  common  instance  of  this  which  we  have  re- 
marked, occurs  in  the  eggs  of  spiders;  patches  of 
which  may  be  found  almost  everywhere  under  the  cross 
bars  of  palings,  and  the  copings  and  corners  of  walls. 
Though  spiders,  for  the  most  part,  not  only  cover  their 
eggs  with  a  thick  envelope  of  silk,  but  also  remain  near 
to  protect  them  from  enemies,  yet  a  small  four  winged 
fly  (Cryptus,  FABR.),  and,  if  we  are  not  mistaken, 
two-winged  flies  (Muscidce,  LEACH),  also,  outbrave 
the  danger  of  being  caught  and  immolated  by  the  mo- 
ther spider,  and  introduce  their  eggs  either  into  or 
among  those  of  their  powerful  enemy.  These  spiders' 
eggs  are  subsequently  feasted  upon  by  the  progeny  of 
the  flies,  —  a  very  natural  reprisal  for  the  ravages 
committed  by  this  carnivorous  race  upon  the  whole 
generation  of  their  fellows.  That  the  mother  flies  ac- 
tually pierce  the  eggs  of  other  insects  was  observed 
before  the  year  1730,  by  the  accurate  Vallisnieri,  who 
says,  '  I  have  seen  with  my  own  eyes  a  certain  kind 
of  wild  flies  deposit  their  eggs  upon  other  eggs,  and 
bore  and  pierce  others  with  an  ovipositor  (aculeus), 
by  means  of  which  they  have  introduced  the  egg.'* 
Count  Zinanni,  another  Italian  naturalist,  told  Reau- 
mur, that,  his  attention  being  attracted  by  a  small 
ichneumon  fluttering  about  the  eggs  of  butterflies, 
he  soon  observed  it  alight  and  fix  upon  one  of  these 
eggs  ;  and,  without  being  incommoded  by  his  ob- 
serving her  proceedings  through  a  strong  magnifier, 

*  Vallisnieri,  Lettere,  80. 


64  INSECT    TRANSFORMATIONS. 

she  bent  her  ovipositor,  and  plunged  it  into  the  egg. 
She  performed  the  same  operation  upon  many  other 
eggs,  which  he  carefully  put  under  cover;  and  in  about 
three  weeks  had  from  them  a  brood  of  flies  of  the  same 
species  with  the  one  whose  remarkable  proceedings  he 
had  watched.* 

A  writer  in  the  Magazine  of  Natural  History  (Jan. 
1830),  gives  an  account  of  a  numerous  brood  of  a 
very  minute  species  of  ichneumon,  supposed  to  be  an 
egg  parasite  (Platygaster  ovulorum  ?  STEPHENS), 
which  was  produced  from  the  caterpillars  of  the  large 
white  cabbage  butterfly  (Pontia  Brassicce).  Having 
enclosed  a  number  of  these  in  a  wire  cage,  five  or  six 
of  them  soon  left  off  feeding,  and  crawled  about  the 
cage.  *  June  30,'  he  proceeds,  c  I  found  them  rest- 
ing on  large  clusters  of  minute  cocoons  of  an  ovate 
form,  the  largest  not  exceeding  two  lines  in  length,  and 
about  the  thickness  of  a  caraway-seed.  Each  was  en- 
veloped with  a  fine  yellow  silk,  resembling  that  of  the 
common  silkworm  (Bombyx  Mori).  On  these  clus- 
ters the  caterpillars  remained  the  whole  day  without 
moving.  Fresh  leaves  were  given  to  the  rest;  but  in 
the  course  of  the  day  they  all  left  off  feeding,  crawled 
about  the  cage,  but  underwent  no  other  change. 
Early  next  day,  I  found  they  had,  with  the  exception 
of  two  or  three,  all  ejected  the  parasitical  progeny  they 
had  been  impregnated  with;  and,  like  the  preceding 
caterpillars,  continued  resting  on  the  clusters  they 
had  formed:  the  remaining  three  followed  the  ex- 
ample of  the  others;  and  the  last  operation  of  these 
devoted  caterpillars  was  to  envelope  each  cluster  in 
a  veil  formed  of  the  most  delicate  web.'")"  It  is 
not  a  little  interesting  to  remark,  that  this  circum- 
stance corroborates  the  statement  before  given  from 

*  Reaumur,  Mem.  vol.  vi,  p.  297. 
t  Loudon's  Mag.  Nat.  Hist,  iii,  51. 


PARASITE    INSECTS.  65 

Goedart,  and  disbelieved  by  Reaumur  and  subse- 
quent naturalists:  but  we  think  it  so  very  extra- 
ordinary, that  we  are  much  inclined  to  think  the 
observer  (T.  H.  of  Clapham)  has  unwittingly  fallen 
into  mistake.  '  Some  of  them,'  he  continues,  '  ex- 
ecuted the  task;  but  the  greater  part  were  too  feeble 
to  complete  it;  and  in  the  course  of  three  days 
more  they  became  motionless,  and  gradually,  one 
after  another,  fell  shrivelled  and  exhausted  to  the 
bottom  of  the  cage.'  Some  of  the  clusters  contained 
upwards  of  a  hundred  cocoons,  and  others  not  more 
than  sixty.  By  July  12,  the  perfect  flies  made 
their  appearance  by  opening  a  sort  of  lid  at  the  end 
of  each  cocoon.  The  flies  seem  to  differ  little, 
except  in  size,  from  the  common  ichneumon  of  the 
same  caterpillar  (Micro gaster  glomeratus ;)  but,  sup- 
posing them  to  be  in  the  first  instance  egg  parasites, 
they  must  have  been  deposited  among,  not  in  the 
eggs  of  the  butterfly. 

The  minuteness  of  some  of  these  parasite  insects 
may  be  partly  conceived  from  the  fact  mentioned  by 
Bonnet,  —  that  the  egg  of  a  butterfly,  not  bigger  than 
a  pin's  head,  is  sufficient  to  nourish  several  of  them; 
for  out  of  twenty  such  eggs  of  butterflies,  a  pro- 
digious number  (une  quantite  prodigieuse)  were 
evolved.*  Few  species  of  the  plant-lice  (Aphides) 
are  a  great  deal  larger  than  the  butterfly's  eggs  de- 
scribed by  Bonnet;  yet  these  also  have  a  parasitical 
enemy  (Microgaster  dlphidum,  SPIN  OLA),  which 
plunges  its  eggs  in  their  bodies;  but  the  larvaB, 
when  hatched,  are  by  no , means  safe,  being  liable 
to  the  attacks  of  ^bother  fly  of  the  same  family 
(Gelis  agilis,  THUNBERG),  as  Dr  Turton  informs 
us.| 

*  Bonnet,  CEuvres,  Svo,  ii,  344.  Kirby,  referring  to  this 
passage,  assigns,  by  mistake,  only  two  to  each  egg.  Introd. 
i,  342. 

t  Transl.  of  Linn,  iii,  48. 

VOL.    VI.  6* 


66  INSECT    TRANSFORMATIONS. 

It  is  not  common,  however,  for  the  ichneumon 
flies  to  deposit  their  eggs  in  the  bodies  of  perfect 
insects,  as  in  most  cases  they  prefer  the  eggs,  larvae, 
or  pupae;  but  instances  are  on  record  of  their  grubs 
having  been  found  in  the  former.  The  troublesome 
cock-roach  (Blatta)  is  selected  by  a  parasite  fly 
(Evania  apendigaster,  FABR.),  as  remarkable  in 
form  as  it  is  rare  in  occurrence,  in  Britain  at  least. 
It  has  been  found  in  the  vicinity  of  London;  but, 
were  it  abundant,  it  might  tend  to  reduce  the  num- 
bers of  these  black  beetles,  as  they  are  incorrectly 
termed,  the  pests  of  the  kitchen. 


Magnified  view  of  a  parasite  fly  (Evania  apendigaster). 

An  insect  parasite,  still  more  singular  in  form, 
and  of  still  rarer  occurrence,  was  discovered  by 
Kirby,  above  thirty  years  ago,  on  the  black  bronze 
bee  (Jlndrena  nigrocenea,  STEPHENS).  '  I  had  pre- 
viously,' he  remarks,  £  more  than  once  observed 
upon  other  species  something  that  I  took  to  be  a  kind 
of  Jlcarus  which  appeared  to  be  immovably  fixed 
just  at  the  inosculations  of  the  dorsal  segments  of  the 
abdomen.  At  length,  finding  three  or  four  upon  a 
specimen  of  this  bee,  I  determined  not  to  lose  the 
opportunity  of  taking  one  off  to  examine  and  de- 
scribe; but  what  was  my  astonishment,  when,  upon 
my  attempting  to  disengage  it  with  a  pin,  I  drew 
forth  from  the  body  of  the  bee  a  white  fleshy  larva, 


PARASITE    INSECTS.  67 

a  quarter  of  an  inch  in  length,  the  head  of  which  I 
had  mistaken  for  an  acarus!  (bee-louse).  After  I 
had  examined  one  specimen,  I  attempted  to  extract 
a  second;  and  the  reader  may  imagine  how  greatly 
my  astonishment  was  increased,  when,  after  I  had 
drawn  it  out  but  a  little  way,  I  saw  its  skin  burst, 
and  a  head  as  black  as  ink,  with  large  staring  eyes 
and  antennae,  consisting  of  two  branches,  break  forth, 
and  move  itself  briskly  from  side  to  side.  It  looked 
like  a  little  imp  of  darkness  just  emerged  from  the 
infernal  regions.  My  eagerness  to  set  free  from  its 
confinement  this  extraordinary  animal  may  be  easily 
conjectured.  Indeed  I  was  impatient  to  become 
better  acquainted  with  so  singular  a  creature.  When 
it  was  completely  disengaged,  and  I  had  secured  it 
from  making  its  escape,  I  set  myself  to  examine  it  as 
accurately  as  possible;  and  I  found,  after  a  careful 
inquiry,  that  I  had  got  a  nondescript,  whose  very 
class  seemed  dubious.'*  Of  the  manner  in  which 
this  singular  insect  (Stylops)  introduced  its  eggs 
into  the  body  of  a  bee  nothing  is  yet  known,  and  its 
rarity  puts  it  out  of  the  reach  of  the  most  eager 
observers.  Several  species  of  the  same  genus  have 
since  been  found  near  London,  and  an  allied  genus 
(Xenos)  has  since  been  discovered  parasite  in  wasps 
by  Professor  Peck,  in  America. 


Bee  Parasite.    (Stylops  Melittce,  Kirby.) 

De  Geer  was  one  day  much  surprised  to  ob- 
serve a  small  white  grub  sucking  the  body  of  a  young 
spider  (Epeira  diadema),  having  attached  itself 

*  Monogr.  Ap.  Angl.  ii,  113. 


68  INSECT    TRANSFORMATIONS. 

firmly  to  the  abdomen.  Having  put  it  into  a  glass, 
he  remarked  a  few  days  afterwards,  that  the  spider 
had  spun  the  outline  of  a  vertical  web,  had  stretched 
threads  from  the  top  to  the  bottom,  and  from  one 
side  to  the  other  of  the  glass,  together  with  the  rays 
of  a  net,  but  without  the  circular  threads.  The  most 
singular  circumstance  was,  that  the  parasite  grub  was 
suspended  in  the  centre  of  this  web,  where  it  spun  its 
cocoon,  while  the  exhausted  spider  had  fallen  dead  to 
the  bottom  of  the  glass.* 

These  examples  will  suffice  to  prove  the  anxious 
care  of  the  mother  insects  in  depositing  their  eggs 
where  their  progeny  may  find  abundance  of  food. 
The  tact  with  which  they  discover  this  is  one  of  those 
mysteries  of  nature  which  are  apparently  beyond 
the  penetration  of  man  ever  to  discover;  for  it  is 
seldom  that  the  mother  insect  herself  feeds  upon  the 
game,  or  similar  substances,  as  her  larva?,  and  yet 
she  is  well  aware  of  what  is  appropriate  for  them. 
The  ichneumon  flies,  whose  history  we  have  just 
been  sketching,  eat  little,  except,  perhaps,  a  small 
quantity  of  honey  from  the  nectary  of  a  flower, 
and  yet  they  know  that  their  progeny  must  be 
fed  by  living  insects;  the  butterflies  and  moths, 
whose  scanty  repast  also  consists  solely  of  the  honey 
of  flowers,  never  make  a  provision  of  this  for  their 
caterpillars,  but  deposit  their  eggs  on  plants  and 
trees  where  their  young  may  eat  abundantly  of 
leaves  or  other  parts  c  after  their  kind.'  In  making 
these  selections,  each  species  exhibits  some  pecu- 
liarity well  worthy  of  observation.  Some  confine 
themselves  to  one  particular  sort  of  plant,  and  never 
select  any  other;  some  make  choice  indifferently  of 
two  or  three  sorts;  while  others  take  a  wider  range, 
and  fix  upon  plants  of  very  different  qualities.  To 
exemplify  this,  we  might  mention  some  thousands  of 

*  De  Geer,  Memoires,  vol.  ii,  p.  863. 


LOCALITIES    OF    VARIOUS    SPECIES.  69 

instances,  but  it  will  be  sufficient  to  say,  that  we  never 
find  the  eggs  of  the  small  tortoise-shell  butterfly 
(Vanessa  urticce)  on  any  plant  but  the  nettle;  its 
congener,  the  painted  lady  (Cynthia  cardui,  STE- 
PHENS), though  it  prefers  the  spear-thistle,  is  some- 
times found  on  the  nettle,  as  is  the  comma  ( Va- 
nessa C.  JUbuni),  though  it  seems  to  prefer  the  hop; 
while  we  have  found  the  eggs  of  the  lackey  moth 
(Clisiocampa  ntustria)  on  almost  every  bush  and 
tree,  from  the  sweetbriar  to  the  oak,  in  woods, 
hedges,  orchards,  and  gardens,  without  any  apparent 
preference  beyond  the  accident  of  the  mother  moth 
alighting  on  a  particular  branch.  In  the  same  way 
almost  all  those  which  deposit  their  eggs  on  salad 
plants,  such  as  the  great  tiger  (Jlrctia,  Caja,  STE- 
PHENS), will  as  readily  select  the  nettle  as  the  lettuce 
or  dandelion.* 

It  is  worthy  of  remark  that  our  native  insects  fre- 
quently make  choice  of  exotic  plants,  by  means  of 
the  instinctive  tact  which  enables  them  to  discover 
such  as  suit  their  purpose.  The  death's-head  hawk 
moth  (Jlcheronlia  Jltropos),  for  example,  is  now 
usually  found  on  the  potatoe  and  the  jasmine,  but 
previous  to  the  introduction  of  these  into  Britain,  it 
probably  confined  itself  to  the  bitter  sweet  ( Solanum 
dulcamara).  We  have  known  the  moth  taken  in 
Ayrshire,  where  this  plant  is  abundant.  An  instance 
in  point  has  just  occurred  to  us  in  one  of  the  minute 
leaf-miners.  Upon  the  leaf  of  an  exotic  plant 
(Cineraria  cruenta)  kept  in  a  garden-pot  in  our 
study,  we  were  not  a  little  surprised  to  observe  the 
tortuous  windings  of  a  miner,  considerably  different 
in  the  outline  from  any  we  had  before  examined. 
Though  it  was  so  late  as  December,  also,  the  grub 
seemed  very  active,  and  would  sometimes  mine  nearly 
half  an  inch  of  the  leaf  in  the  course  of  the  day.  It 

*  J.  R. 


70  INSECT    TRANSFORMATIONS. 

was  transformed  within  the  leaf,  in  a  few  days,  into 
a  pupa,  and  being  put  under  a  bell-glass,  a  small  two- 
winged  fly  (Tephrilis  Serratulce?  )  made  its  appear- 
.ance  in  about  a  fortnight.  In  some  garden-pots,  in 
another  room  of  the  same  house,  were  exotic  plants 
of  the  American  groundsel  (Senecio  elegans},  the 
leaves  of  which  were  crowded  with  miners,  whose 
paths,  however,  were  so  very  different  as  to  indicate 
a  different  species;  but  upon  their  transformation 
into  perfect  insects,  they  turned  out  exactly  the  same. 
They  proved,  indeed,  to  be  the  same  with  the  leaf 
miners  of  the  swine-thistle  (Sonchus  oleraceus), 


Leaf-mining  .  maggots,  a,  the  fly  (Tephritis  Serratula  ?)  6, 
mined  leaf  of  sow-thistle  (Sonchus  oleraceus).  c  c,  mined  leaf 
pf  Senecio  clegans,  d  <Z,  mined  leaf  of  Cineraria  entente. 


LOCALITIES    OF    VARIOUS    SPECIES.  71 

numerous  specimens  of  which  we  collected  in  the 
immediate  vicinity;  but  the  flies  of  these,  from  their 
previous  exposure  to  the  cold  out  of  doors,  did  not 
appear  till  a  month  later.  It  is  worthy  of  remark, 
that  the  two  exotic  plants  are  of  the  same  natural 
family  (Composites) ,  yet,  notwithstanding  the  simi- 
larity of  the  common  groundsel  (Senecio  vulgaris)  to 
the  American,  not  one  leaf  of  the  former  was  found 
mined,  though  it  is  an  abundant  native  plant.* 

It  is  no  less  remarkable,  that  the  mother  insects 
of  the  larvas  which  live  solitary  and  those  which 
live  in  society  take  care  to  deposit  their  eggs  with 
regard  to  the  respective  destinations  of  their  pro- 
geny. In  our  earlier  studies  we  remember  being  much 
interested  with  Harris's  description  of  the  admirable 
butterfly  ( Vanessa  Jltalanta)^  flitting  rapidly  and 
stealthily  from  field  to  field,  and  depositing  only  a 
single  egg  on  a  single  nettle  in  each,  as  if  she  were 
afraid  of  overstocking  one  place  and  leaving  others 
uninhabited  by  her  descendants.!  Our  subsequent 
observation  of  the  mariners  of  the  insect  itself  has  led 
us  to  doubt  the  accuracy  of  Harris;  for  we  think  it 
will  hold  as  a  pretty  general  principle,  that  the  mo- 
thers of  solitary  caterpillars,  for  the  most  part,  deposit 
several  eggs  on  the  same  plant,  often  at  no  great 
distance,  and  sometimes  on  the  same  leaf.  No  class 
of  caterpillars  could  well  be  considered  more  solitary 
than  those  of  the  hawk  moths  (Sphingidce,  LEACH), 
yet  we  have  found  from  two  to  three  eggs  of  that 
of  the  popular  hawk  ( Smerinthus  Populi)  upon  the 
same  leaf,  and  a  similar  number  of  the  eggs  of  the 
puss  moth,  the  larva  of  which  is  also  solitary,  on  one 
leaf  ;J  while  of  the  admirable  butterfly  above  alluded 
to,  we  found,  in  1825,  as  many  as  from  three  to  six 
on  every  plant  in  a  small  patch  of  about  a  dozen 

*  J.  R.         t  See  Harris's  Aurelian,  vi,  fol.  Lond.  1778. 
|  See  Insect  Architecture,  p.  192. 


72  INSECT    TRANSFORMATIONS. 

nettles,  in  Copenhagen-fields,  Islington.  A  similar 
deposition  of  eggs  is  made  by  several  of  the  mothers 
of  the  subsolitary  caterpillars  which  live  in  the  wood 
of  trees.  Of  this  we  had  a  good  example  in  the 
clear  under-wing  (JEgeria  asiliformis) ,  above  a  score 
of  the  small  black  eggs  of  which  we  found  deposited 
in  a  scattered  manner  on  the  trunk  of  a  single  poplar 
at  Lee.* 

The  most  singular  disposal  of  eggs  with  which  we 
are  acquainted  in  the  economy  of  insects,  is  exempli- 
fied in  the  common  gnat  (  Culex  pipiens,  LINN.)  It 
is  admirably  described  by  Reaumur,  though  it  seems 
first  to  have  been  discovered  by  Langallo,  who  men- 
tions it  in  a  letter  addressed  to  Redi,  printed  at  Flo- 
rence in  1679  ;  and  by  Alloa,  who  actually  saw  the 
eggs  laid,  and  afterwards  sketched  a  figure  of  them. 
Those  who  wish  to  witness  this  singular  operation, 
must  repair  before  five  or  six  o'clock  in  the  morning 
to  a  pond  or  a  bucket  of  stagnant  water  frequented  by 
gnats  ;  when  Reaumur  went  later  in  the  day  he  was 
always  disappointed. 

The  facts  of  this  disposal  of  her  eggs  by  the  com- 
mon gnat,  are  sufficiently  curious  to  excite  attention 
to  them  ;  and,  therefore,  it  is  not  easily  to  be  under- 
stood how  the  following  erroneous  and  fanciful 
account  originated.  '  The  manner,'  says  Gold- 
smith, *  in  which  the  insect  lays  its  eggs  is  particu- 
larly curious  ;  after  having  laid  the  proper  number  on 
the  surface  of  the  water,  it  surrounds  them  with  a 
kind  of  unctuous  matter,  which  prevents  them  from 
sinking,  but  at  the  same  time  fastens  them  with  a 
thread  to  the  bottom,  to  prevent  their  floating  away, 
at  the  mercy  of  every  breeze,  from  a  place  the  warmth 
of  which  is  proper  for  their  production,  to  any  other 
where  the  water  may  be  too  cold,  or  the  animals,  its 
enemies,  too  numerous.  Thus  the  insects,  in  their 

*  J.  R. 


RAFT  OF  EGGS  OF  THE  GNAT.          73 

egg  state,  resemble  a  buoy  which  is  fixed  by  an 
anchor.  As  they  come  to  maturity,  they  sink  deeper, 
and  at  last,  when  they  leave  the  egg  as  worms,  creep 
to  the  bottom."**  This  fable,  which  was  first  men- 
tioned by  Pliny,  is  repeated  verbatim  by  JBingley.'f 
The  impossibility  of  a  gnat  spinning  a  thread,  and 
plunging  into  the  water  to  fix  it  at  the  bottom,  never 
struck  these  writers. 

We  are  more  anxious  to  expose  these  erroneous 
accounts,  from  a  persuasion  that  a  taste  for  natural 
history  has  been  more  injured  by  numerous  similar 
statements,  which  could  not  be  verified  by  a  student, 
in  many  popular  works,  than  by  the  driest  skeleton 
descriptions  of  those  who  have  merely  pursued  Natural 
History  as  a  science  of  names. 

The  problem  of  the  gnat  is  to  construct  a  boat- 
shaped  raft,  which  will  float,  of  eggs  heavy  enough  to 
sink  in  water  if  dropped  into  it  one  by  one.  The 
eggs  are  nearly  of  the  pyramidal  form  of  a  pocket 
gunpowder-flask,  rather  •  pointed  at  the  upper  and 
broad  at  the  under  end,  with  a  projection  like  the 
mouth  of  a  bottle.  The  first  operation  of  the  mother 
gnat  is  to  fix  herself  by  the  four  fore-legs  to  the  side 
of  a  bucket,  or  upon  a  floating  leaf,  with  her  body 
level  with  and  resting  upon  the  surface  of  the  water, 
excepting  the  last  ring  of  the  tail,  which  is  *la  little 
raised  ;  she  then  crosses  her  two  hind  legs  in  form  of 
an  X,  the  inner  opening  of  which  is  intended  to  form 
the  scaffolding  of  her  structure.  She  accordingly 
brings  the  inner  angle  of  her  crossed  legs  close  to  the 
raised  part  of  her  body  and  places  in  it  an  egg,  covered, 
as  is  usual  among  insects,  with  a  glutinous  fluid.  On 
each  side  of  this  egg  she  places  another,  all  which 
adhere  firmly  together  by  means  of  their  glue,  and 
form  a  triangular  figure  thus  J  *,  which  is  the  stern 

*  Goldsmith,  Animated  Nature,  vi,  337. 
t  Bingley,  Animal  Biography,  iii,  439,  Sd.ed. 
7 


74  INSECT    TRANSFORMATIONS. 

of  the  raft.  She  proceeds  in  the  same  manner  to  add 
egg  after  egg  in  a  vertical  (not  a  horizontal)  position, 
carefully  regulating  the  shape  hy  her  crossed  legs; 
and  as  her  raft  increases  in  magnitude,  she  pushes  the 
whole  gradually  to  a  greater  distance,  and  when  she 
has  about  half-finished  she  uncrosses  her  legs  and 
places  them  parallel,  the  angle  being  no  longer  neces- 
sary for  shaping  the  boat.  Each  raft  consists  of 
from  two  hundred  and  fifty  to  three  hundred  and 
fifty  eggs,  which,  when  all  laid,  float  on  the  water 
secure  from  sinking,  and  are  finally  abandoned  by 
the  mother.  They  are  hatched  in  a  few  days,  the 
grubs  issuing  from  the  lower  end;  but  the  boat,  now 
composed  of  the  empty  shells,  continues  to  float  till  it 
is  destroyed  by  the  weather.* 


Gnats  forming  their  egg  boats,  a,  represents  the  commencement 
of  the  boat  of  eggs  ;  6,  the  boat  about  two-thirds  completed  j  c, 
the  perfect  boat  resting  on  the  surface  of  the  water. 

Kirby  justly  describes  this  little  vessel  as  resembling 
a  London  wherry,  being  sharp  and  higher,  as  sailors 
say,  fore  and  q/£,  convex  below  and  concave  above, 
and  always  floating  on  its  keel.  '  The  most  violent 
agitation  of  the  water,'  he  adds,  c  cannot  sink  it,  and 
what  is  more  extraordinary,  and  a  property  still  a  de- 
sideratum in  our  life-boats,  though  hollow,  it  never  be- 

*  Reaumur,  Mem,  iv,  p.  621. 


RAFT  OF  EGGS  OF  THE  GNAT.         75 

comes  filled  with  water,  even  though  exposed.  To 
put  this  to  the  test,  I  placed  half  a  dozen  of  these 
boats  upon  the  surface  of  a  tumbler  half-full  of  water: 
I  then  poured  upon  them  a  stream  of  that  element 
from  the  mouth  of  a  quart  bottle  held  a  foot  above 
them.  Yet  after  this  treatment,  which  was  so  rough 
as  actually  to  project  one  out  of  the  glass,  I  found 
them  floating  as  before  upon  their  bottoms,  and  not  a 
drop  of  water  within  their  cavity.'*  We  have  re- 
peatedly pushed  them  to  the  bottom  of  a  glass  of  wa- 
ter; but  they  always  came  up  immediately  to  the  sur- 
face apparently  un wetted. 


Magnified  view  of  the  boat  of  gnats'  eggs. 

We  have  contented  ourselves  with  giving  here  only 
a  few  examples  of  the  maternal  care  which  is  display- 
ed by  insects  in  depositing  their  eggs,  though  we 
could  have  filled  the  volume  with  similar  details. 
The  instincts  which  are  thus  displayed  are  of  the 
most  interesting  description;  and  they  cannot  fail  to 
knpress  the  most  careless  observer  with  a  deep  reve- 
rence of  that  providential  wisdom  by  which  they  are 
implanted  in  these  small  and  feeble  creatures  for  the 
maintenance  of  their  race.  But  it  is  not  essential,  in 
order  to  produce  this  reverence,  to  exaggerate  the  cir- 
cumstances under  which  these  remarkable  peculiari- 
ties are  displayed.  The  infallibility  of  the  instinct  of 
insects  in  such  cases  is,  in  most  books  of  natural  his- 
tory, maintained  to  be  without  exception.  <  Led  by 
an  instinct,'  says  Kirby  and  Spence,  <  far  more  un 

*  Introd.  iii,  p.  32. 


76  INSECT    TRANSFORMATIONS. 

erring  than  the  practised  eye  of  the  botanist,  she  re- 
cognizes the  plant  the  moment  she  approaches  it.'* 
And  again,  they  talk  of  the  c  unerring  foresight  with 
which  the  female  deposits  her  eggs  in  the  precise 
place  where  the  larvae  when  excluded  are  sure  to  find 
suitable  food.'t  This  unconditional  position  requires 
however,  to  be  considerably  modified  to  make  it  cor- 
respond with  the  facts.  The  experiment  we  gave  from 
Redi  in  our  first  chapter,  in  which  the  carnivorous 
flies  laid  their  eggs  on  the  silk  and  paper  covering 
tainted  meat,  will  occur  to  every  reader  as  one  striking 
exception;  and  we  can  mention  several  others  still 
more  marked.  When  Dr  Arnold  discovered  that 
most  singular  parasitic  plant,  the  krubut,  of  Sumatra, 
(Rafflesia  Jlrnoldii,  BROWN,)  which  consists  of  a 
flower  only,  without  leaf  or  stem,  and  of  the  extra- 
ordinary diameter  of  three  feet,  he  perceived  a  swarm 
of  flies  hovering  over  the  nectary,  an?,  apparently 
laying  their  eggs  in  its  substance,  mistaking  it  most 
probably  for  carrion,  as  it  smelt  like  tainted  beef.J 
A  similar  mistake  is  committed  in  ,ur  own  country, 
when  the  cc  union  blow-fly  (Muse/,  vom'toria)  lays 
its  eggs  in  ccetid  funguses  (Phalli,  Agarici,  &c), 
apparently  ;  -er  the  .notion  that  these  are  genuine 
carrion. §  This  may  be  more  particularly  observed 
on  the  singular  class  of  plants,  stapelias,  which  are 
so  common  in  our  hot-houses:  whole  families  of  mag- 
gots are  constantly  born  to  starve  in  their  foetid  flowers. 
These  are  instances  of  the  mistakes  of  instinct  in 
circumstances  where  it  depends  upon  the  information 
of  the  senses  ;  and  similar  mistakes  frequently  occur 
where  the  higher  powers  of  human  rationality  are 
deceived  by  analogous  phenomena.  The  fine  nutty- 
flavour  of  cherry  laurel  water  and  of  prussic  acid 

*  Introd.  i,  p.  340.  t  Ibid,  iii,.p.  65. 

$  R.  Brown,  Linn.  Trans,  vol.  xiii.     $  Smellie,  Philos.   of 
Nat.  Hist. 


MISTAKES    OF    INSECTS.  77 

would  be  certain  to  deceive  the  inexperienced  ;  and 
Majendie's  servant  actuality  fell  an  immediate  victim 
to  her  desire  of  tasting  the  prussic  acid  which  she 
found  in  his  laboratory.  This  would  be  considered 
perhaps  a  mistake  arising  from  the  artificial  habits  ac- 
quired in  society,  by  those  who  maintain  that  animals, 
guided  by  instinct,  never  mistake  poison  for  food.  But 
we  may  add  another  curious  instance  or  two  of  simi- 
lar mistakes  in  the  inferior  races. 

The  common  earth-worm  (Lumbricus  terrestris) 
is  instinctively  afraid  of  moles  ;  and  no  sooner  does  it 
hear  any  subterranean  noise,  or  feel  any  shaking  of 
the  ground,  similar  to  those  indicative  of  the  approach- 
ing movements  of  its  enemy,  than  it  makes  a  speedy 
escape  to  the  surface.  Every  boy  knows  how  to  take 
advantage  of  this  to  procure  fish-baits,  by  thrusting  a 
spade  or  stake  into  the  ground,  and  moving  it  backwards 
and  forwards,  to  imitate  the  advance  of  a  mole  burrow- 
ing in  search  of  prey.  The  worm,  unable  from  its  in- 
stinct to  discriminate  between  its  subterranean  enemy 
and  the  spade,  darts  into  day-light,  and  is  instantly  cap- 
tured for  the  boy's  bait-bag.  The  lapwing  (  Vancllus 
cristatus,  MEYER),  it  is  stated  by  Dr  Anderson  in  his 
'  Bee,7  is  aware  of  this  instinctive  fear  in  the  earth- 
worm of  subtewanean  concussions  or  noises  ;  and 
when  it  cannot  find  sufficiency  of  slugs,*  &c,  above 
ground,  it  pats  with  its  feet,  till  the  earth-worms,  mis- 
taking it  for  an  advancing  mole,  come  forth  to  be  feast- 
ed upon. 

It  is  well  known  that,  whenever  a  hawk  appears, 
he  is  immediately  surrounded  by  a  host  of  small  birds, 
particularly  swallows,  which  dart  at  him  and  tease  him, 
for  the  purpose,  as  maybe  supposed,  of  distracting  his 
attention,  on  the  principle  that  *  wealth  makes  wit  wa- 

*  «  Nourriture  ;  —  insectes,  araign?  es,  vers,  et  petits  lima 
Sons.'  TEMMINCK,  Manuel  d'Ornithologie,  p.  552,  2d  edit. 

7* 


78  INSECT    TRANSFORMATIONS. 

ver.'  Be  this  as  it  may,  the  cuckoo,  which  bears  a 
strong  resemblance  to  a  hawk  when  on  the  wing,  is 
certain  to  be  accompanied  by  a  similar  retinue  of  small 
birds  wherever  it  flies.  In  the  north  this  is  so  com- 
monly observed,  that  the  cuckoo  is  popularly  believed 
to  be  always  attended  by  a  tilling  or  pippet  (Anihus 
pralensis,  BECHSTEIN),  which,  it  is  further  imagined, 
has  been  its  stepmother  and  nurse  from  the  egg  :  this, 
indeed,  is  the  bird  whose  nest  the  cuckoo  most  fre- 
quently selects  to  deposit  the  eggs  which  she  so 
strangely  and  unnaturally  abandons;  though  it  is  more 
probable  that  it  is  not  on  this  account,  but  because  she 
appears  to  be  a  hawk,  that  the  pippet  and  other  small 
birds  persecute  her. 

Linnaeus  records  in  his  c  Lachesis  Lapponica,'  that 
at  Tornea  there  is  a  meadow,  or  bog,  full  of  water- 
hemlock  ( Cicula  rirosa),  which  annually  destroys  from 
fifty  to  a  hundred  head  of  cattle.  It  seems  that  they 
eat  most  of  it  in  spring,  when  first  turned  into  the  pas- 
ture, partly  from  their  eagerness  for  fresh  pasture,  and 
partly  from  their  long  fasting  and  greediness,  the  herb- 
age being  then  short.  Besides,  from  the  immersion 
of  the  hemlock  under  water,  it  may  not  have  the  pro- 
per scent  to  deter  them.  A  similar  destruction  of  cat- 
tle from  the  same  cause  occurs  in  th$  wide  meadows 
of  Leinings.* 

*  J.  R.,  in  Mag.  of  Nat.  Hist.,i,  374. 


CHAPTER  IV. 

Hibernation  of  Insect  Eggs.— Ingenuity  of  Moths. —Singularities  of 
Cochenille  Insects  and  of  Spiders.  —  Experiments  of  Spallanzani  and 
John  Hunter. 

THE  assertion  of  Paley  that  £  the  human  animal  is 
the  only  one  which  can  clothe  itself,'*  though  it  ac- 
cords with  what  is  known  of  quadrupeds,  birds,  and 
fishes,  by  no  means  holds  good  in  the  insect  world,  in 
which  it  may  be  disproved  by  the  most  superficial 
observer.^  Men,  indeed,  proceed  by  means  of  rea- 
soning and.  experiment  to  the  discovery  of  such  ma- 
terials as  a're  best  fitted  for  protecting  their  bodies 
against  the  vicissitudes  of  temperature,  and  other 
changes  of  weather  ;  while  insects  are  taught  by  the 
Governor  of  the  Universe  to  select  instinctively  the 
best  materials  for  their  clothing.  This  is  exemplified 
in  a  very  remarkable  manner  in  the  coverings  made 
by  different  families  for  protecting  their  eggs,  as  we 
shall  now  describe. 

The  maternal  affection  of  the  eider  duck  (Jlnas 
mollissima,  LINN.)  has  frequently  been  celebrated  by 
naturalists,  from  her  stripping  the  down  from  her  own 
breast  to  form  her  nest,  a  circumstance  which  is  also 
exemplified  in  the  common  rabbit  ;  but  both  of  these 
animals  are  outrivalled  by  more  than  one  moth  :  — 
for  the  latter,  not  contented  with  a  nest  made  of  their 
own  down,  take  pains  to  cover  with  it  each  individual 
egg.  The  provision  which  nature  has  made  for  this 
purpose  is  worthy  of  attention.  The  female,  for  ex- 
ample, of  the  gypsey  moth  (Hypogymna  dispar)  has 
the  hinder  parts  of  her  body  thickly  clothed  with  a 

*  Natural  Theology,  p.  230,  llth  edit. 

t  See  « Insect  Architecture,*  chaps,  x,  xii,  &e. 


80  INSECT    TRANSFORMATIONS. 

soft  down  of  a  hair-brown  colour,  which  is  wanting 
in  the  male,  evidently  because  to  him  it  would  be  of 
no  use.  As  a  covering  for  her  own  body,  it  can  be 
of  but  small  service,  since  she  emerges  from  her 
pupa-case  during  the  hot  days  of  August,  and  does 
not  usually  live  more  than  a  week  or  a  fortnight.  Its 
chief  or  sole  purpose,  therefore,  is  to  furnish  a  cover- 
ing for  her  eggs. 

When  about  to  lay,  the  mother  gypsey  moth  places 
herself  on  the  trunk  of  an  oak  or  an  elm,  invariably 
with  her  head  downwards,  the  reason  of  which  posi- 
tion will  be  immediately  explained.  With  the  aid 
of  her  legs,  which  are  too  short  to  be  used  like 
those  of  the  gnat  by  way  of  rule  and  compass,  she 
contrives  to  place  her  eggs  in  the  form  of  an  inverted 
cone.  She  first  makes  a  little  bed  of  this  down,  into 
which  she  thrusts  the  egg  intended  for  the  point  of 
her  cone;  and  this  egg,  being  covered  with  adhesive 
gluten,  attaches  around  it  all  the  hairs  of  the  down 
with  which  it  comes  in  contact,  and  also  sticks  to  the 
bark  of  the  tree,  from  its  being  pushed  home.  Pro- 
ceeding in  the  same  manner,  she  continues  for  seve- 
ral hours  adding  to  the  mass  ;  but  she  does  not  in 
general  finish  the  operation  in  less  than  two  days, 
indulging  in  occasional  rests  when  fatigued  with  her 
labour.  At  intervals,  also,  she  takes  care  to  protect 
the  eggs  placed  in  the  cone  with  an  exterior  covering 
of  the  same  down.  There  is  one  part  of  these  ope- 
rations not  a  little  remarkable.  In  the  bed  which  she 
first  makes  for  the  eggs,  the  hairs  of  the  down  either 
point  at  right  angles  to  the  bark  of  the  tree,  or  at 
least  are  tossed  down  with  little  regularity  ;  but  in 
the  external  coping,  which  is  designed  to  keep  out  the 
winter  rains,  the  hairs  are  carefully  placed  in  a  sloping 
direction,  like  the  tiles  on  a  house,  or  the  pile  of  a 
well  brushed  hat,  pointing  downwards  towards  the 
base  of  the  cone.  The  latter  is  usually  concave,  be- 


JNGSNUITY    OF    MOTHS.  81 

cause,  when  the  moth  takes  her  occasional  rests,  she 
never  moves  from  the  spot,  but  remains  with  her  tail 
thrust  in  amongst  the  eggs.  We  have  given  these 
details  from  observations  made  in  the  Pare  at  Brus- 
sels, in  August  1829;*  and  our  entomological  readers 
will  perceive,  that  though  they  do  not  disagree  with 
the  facts  observed  by  the  accurate  Reaumur,  we  have 
added  several  particulars  not  mentioned  by  him.! 

In  order  to  preserve  some  specimens  of  the  gypsey 
moth,  which  abounds  in  the  Netherlands,  but  is  rare 
in  most  parts  of  Britain,  we  inclosed  two  or  three  in 
chip  boxes.  Upon  opening  these,  a  short  time  after- 
wards, we  found  that  one  of  the  moths  had  deposited 
a  patch  of  eggs;  but,  instead  of  the  conical  form  which 
the  insect  would  have  chosen  had  she  been  at  liberty, 
she  had  disposed  them  in  the  form  of  a  wheel,  of  which 
her  body  was  the  radius.  This,  of  course,  was  not  so 
much  to  be  wondered  at,  as  it  no  doubt  arose  from  her 
want  of  space  to  proceed  in  the  usual  manner;  but  we 
deem  it  worthy  of  notice  that  this  wheel,  which  was 
about  a  quarter  of  an  inch  broad  in  the  rim,  was  sloped 


o,  female  gypsey  moth,  one-third  the  natural  size,  just  finish 
ing  her  group  of  eggs.  6,  female  gypsey  moth,  with  its  body 
covered  with  down,  c,  circle  of  eggs  covered  with  hair,  and  d, 
conical  mound  of  eggs  covered  with  hair,  laid  by  gypsey  moths 
in  confinement. 

*  J.  R.  t  Reaumur,  Mem.  ii,  101. 


82  INSECT   TRANSFORMATIONS. 

with  the  greatest  regularity,  after  the  manner  of  a  candle 
shade,  and  the  down  tiled  upon  it  all  round.  Another 
of  our  prisoners,  though  precisely  in  the  same  circum- 
stances as  to  space,  instead  of  forming  a  wheel,  piled 
up  her  eggs  in  form  of  a  circular  mound;  but  as  the 
number  of  her  eggs  was  not  a  sixth  part  of  those  of  the 
other,  (probably  from  her  having  deposited  part  before 
we  caught  her,)  this  may  have  induced  her  to  vary 
the  shape  of  the  group.  Like  the  others,  however, 
the  regular  slope  and  tiling  of  the  down  was  carefully 
preserved.*  We  have  now  (April,  1830)  a  numerous 
brood  of  caterpillars  from  these  very  eggs. 

The  eggs,  which  are  thus  deposited  with  so  much 
care,  are  destined  to  abide  all  the  pitiless  pelting  of 
the  storms  of  winter;  for,  although  they  are  laid  in 
August,  they  are  not  hatched  till  the  elm  conies  into 
leaf  in  the  following  spring.  The  covering  of  down, 
accordingly,  from  the  manner  in  which  it  is  tiled  and 
brushed  smooth  by  the  mother  moth,  not  only  protects 
them  from  wet,  but  from  severe  cold,  being  one  of  the 
best  non-conductors  of  heat.  The  experiments  of 
modern  chemical  philosophers  have  proved  beyond  a 
doubt,  that  the  warmest  material  for  clothing  is  not 
what  imparts  most  heat  to  the  body,  but  what  best 
prevents  the  escape  of  the  heat  generated  there.  The 
feeling  of  cold,  therefore,  does  not,  as  might  be  sup- 
posed, arise  from  anything  positively  cold,  but  solely 
from  a  deficiency  of  heat.  On  putting  the  hand,  for 
example,  on  a  piece  of  ice,  the  feeling  of  cold  does 
not  arise  from  cold  given  out  by  the  ice  to  the  hand, 
but  from  the  heat  which  the  ice  takes  from  the  hand, 
which  heat  can  be  actually  traced  in  the  water  formed 
by  the  melting  of  the  ice.  But  when  the  hand  is  laid 
upon  wool,  feathers,  or  down,  these  do  not  feel  cold, 
because  they  do  not  carry  off  the  heat  of  the  skin  so 
rapidly  as  the  ice. 

*  J.  R. 


PROTECTION    OF    EGGS.  83 

It  may  appear  a  little  paradoxical,  though  the  doc- 
trine is  sound,  to  assert  that  down  and  similar  ma- 
terials are  nearly  as  well  calculated  for  protecting  an 
animal  from  excessive  outward  heat  as  from  severe 
cold.  This,  however,  has  been  long  well  known  as  a 
fact  to  the  Neapolitan  peasantry,  who  convey  snow 
from  Mount  Vesuvius  to  Naples  in  the  summer  for  the 
purposes  of  luxury:  they  preserve  it  from  melting  by 
covering  it  with  chaff  and  wool.  It  may  not  be  out 
of  place  to  remark  that  instances  of  this  occur  among 
insects,  precisely  similar  to  what  we  have  just  detailed 
respecting  the  gypsey  moth.  The  brown-tail  and  the 
golden-tail  moths  (Porthesia  auriflua,  and  P.  Chry- 
sorrhcea,  STEPHENS),  whose  caterpillars  spin  them- 
selves a  warm  nest  before  the  setting-in  of  the  winter 
colds,*  seem  no  less  careful  to  protect  their  eggs  from 
the  summer  heats  of  July  and  August,  at  which  time 
they  are  deposited.  The  down  with  which  they  are 
furnished  for  this  purpose  grows  upon  the  tail  of  the 
female  moth,  in  form  of  a  thick  tuft  or  brush,  of  a 
shining  silky  gloss,  and  of  a  different  colour  from  the 
short  hair  on  the  body.  It  may  be  remarked  that 
moths  have  only  a  mouth  tube  for  sucking  honey,  and 


Females  of  the  brown  and  gold-tailed  moths,  showing  the  bunch 
of  down  on  the  tails. 

*  See  '  Insect  Architecture,'  p.  329  —  331. 


84  INSECT    TRANSFORMATIONS. 

no  mandibles  or  jaws,*  like  bees,  wasps,  and  beetles, 
for  performing  any  mechanical  labour;  but  the  moths 
in  question  have  an  organ  admirably  contrived  for 
covering  their  eggs  with  down.  This  consists  of  an 
extensile  instrument,  situated  in  the  tail,  not  unlike 
the  points  of  a  pair  of  sugar-tongs,  and  intended  to 
perform  the  part  of  tweezers  in  pulling  off  the  down, 
and  placing  it  upon  the  eggs.  Having  reared  nume- 
rous broods  of  the  moths  alluded  to,  we  can  testify 
to  the  minute  accuracy  of  Reaumur  in  detailing 
their  proceedings.  He  remarks,  that  though  the 
mother  moth  is  exceedingly  sluggish  (lourde)  in  her 
general  movements,  she  employs  her  tweezers  with 
surprising  quickness,  on  all  sides,  first  to  pull  off  a 
pinch  of  down,  and  spread  it  out,  and  then  to  place  the 
egg  upon  it,  and  cover  it  neatly  over,  and  smooth  the 
down  in  the  proper  direction.  The  nature  of  the  in- 
strument will  be  better  understood  by  the  following 
figures. 


Tweezers  of  the  brown  and  gold-tailed  moths,  magnified. 

Reaumur  has  figured  the  deposition  of  the  eggs 
of  an  insect,  the  species  of  which  is  not  ascertained, 
sent  him  by  a  physician  of  Lucon,  which  are  covered, 
like  the  preceding,  with  down,  but  are  arranged  in  an 
elegant  spiral  form,  as  if  a  lady  would  wind  one  of 
the  ends  of  her  fur  tippet  spirally  round  a  branch, 

*  Savigny,  however,  has  displayed  much  acumen  in  showing 
how  the  suckers  of  moths,  &c,  are  analogous  to  mandibles.  — 
Memoir es  sur  les  Jlnim.  sans  Verteb. 


SPIRAL    FORM    OF  EGGS.  85 

These  eggs  were  extremely  small,  and  the  down  very 
fine,  like  the  short  fur  of  the  beaver,  and  of  a  pretty 
squirrel-gray  colour.  The  eggs  were  oblong,  and 
placed  on  end,  at  right  angles  to  the  branch;  as  was 
also  their  downy  envelope,  which  differed  in  this  re- 
spect from  the  imbricated  and  smoothly  brushed 
coping  of  the  moths  above  described.  There  is  no- 
thing of  this  kind,  says  Reaumur,  which  we  ought  to 
consider  it  difficult  for  an  insect  to  execute,  when  we 
are  acquainted  with  the  admirable  instruments  with 
which  nature  has  furnished  them.* 


Spiral  group   of  eggs  of  an  unknown  moth. 

The  spiral  form  of  eggs  deposited  upon  a  branch 
may,  in  particular  years,  be  seen  in  almost  every 
orchard  and  every  hedge,  being  the  method  followed 
by  the  lackey  moth  (Clisiocampa  neustria,  STE- 
PHENS) and  its  congeners.  The  precise  manner  in 
which  the  mother  lackey  proceeds  has  not,  so  far  as 
we  know,  been  witnessed  by  any  naturalist  ;  and 
though  Reaumur  reared  a  great  number  on  pur- 
pose to  discover  it,  all  his  efforts  proved  unsuccessful. 
An  examination,  however,  of  the  arrangement  of  the 
eggs  themselves,  shows  that  they  are  placed  in  a 
manner  excellently  adapted  to  secure  their  adhesion 
to  the  branch,  and  to  prevent  their  sustaining  injury. 
The  egg  is  somewhat  of  the  form  of  a  funnel-shaped 
wine-glass—broader  at  top  than  at  bottom  ;|  and  it 

I 

*  Reaumur,  Mem.  ii,  107. 

i  See  two  of  these  eggs  figured  in  *  Insect  Architecture,'  p.  19. 
8 


86  INSECT    TRANSFORMATIONS, 

is  worthy  of  remark,  that  this  is  the  precise  form  of 
the  arch-stones  of  a  bridge.  They  are,  in  fact,  built 
together  in  the  arched  form.  This,  together  with 
the  strong  cement  employed  in  uniting  them,  renders 
it  difficult  to  crush  them,  though  considerable  force 
be  used  for  that  purpose;  and  this  even  when  they 
are  slipped  off  the  branch,  round  which  they  are  set 
like  pearls  on  a  bracelet,,  which  is  the  name  given 
them  by  the  French  peasantry.  The  cement,  also,  is 
so  hard,  that  when  pressed  it  resists  the  nail,  though 
it  may  be  pierced  with  the  point  of  a  sharp  knife ;  and 
not  being  soluble  in  water,  '  nor  in  any  other  liquid,' 
says  Swammerdam,  {  which  I  have  tried,'  the  heavi- 
est rain  dashes  upon  the  eggs  without  injury. 


Eggs  of  the  lackey  moth,  wound  spirally  round  a  twig  of  haw- 
thorn 5  natural  size,  and  magnified. 

It  may  be  a  question  with  some,  when  they  com- 
pare these  naked  eyes  of  the  lackey  moth,  exposed  on 
a  bare  branch,  with  the  warm  downy  covering  of  those 
of  the  gypsey  moth,  how  the  former  are  protected 
from  the  colds  of  winter.  This  is  a  question  which 
previous  researches  cannot  fully  answer,  but  one  cir- 
cumstance is  obvious  — -  the  lackey's  eggs  are  many 
degrees  harder  than  those  of  the  gypsey,  which  may 
be  easily  crushed.  Probably  also,  this  may  be  con- 
nected with  their  electrical  state;  and  that  has  always 


HYBERNAT1ON    OF    EGGS.  87 

an  intimate  connexion  with  heat  in  animated  bodies. 
The  living  principle,  to  which  we  shall  by  and  by 
advert,  must  also  be  taken  into  account. 

In  consequence  of  the  minuteness  of  insect  eggs, 
notwithstanding  the  researches  of  enthusiastic  ento- 
mologists, we  are  still  unacquainted  with  by  far  the 
greater  number.  The  hybernation  of  eggs  is,  there- 
fore, a  subject  upon  which  little  is  known..  In  the 
egg  state  insect  life  is,  perhaps,  less  liable  to  acci- 
dents, than  in  a  more  advanced  stage  of  existence; 
and  it  is  most  probable  that  the  greater  number  re- 
main unhatched  during  the  cold  season.  Different 
modes  of  depositing  eggs  are  resorted  to  by  different 
species  of  the  same  genus,  as  may  be  exemplified  in 
the  plant  lice  (Aphides).  It  was  observed  by  De 
Geer,  that  those  of  the  birch  and  the  blackthorn 
(Aphis  Mm,  and  A.  Pruni)  covered  each  egg  indivi- 
dually with  a  white  cottony  down,  detached  from  their 
bodies  by  means  of  their  hind  legs,  and  placed  by  the 
same  means  over  the  eggs.*  But  the  greater  num- 
ber of  this  family  lay  their  eggs  in  an  exposed  situa- 
tion, upon  the  plants  where  the  young,  when  hatched, 
may  find  food.  Thus  Kirby  found  the  small  black 
eggs  of  a  large  species  on  the  buds  of  birch-trees;  and 
we  have  just  discovered  (Jan.  1830)  a  numerous  de- 
posit of  the  eggs  of  the  magpie  plant-louse  (Aphis 
Sambuci)  on  an  elder  tree,  where  the  insect  was 
abundant  the  preceding  summer. "f  These  eggs  are 
exceedingly  minute,  but  easily  observed  on  account  of 
their  shining  black  colour.  They  are  placed  in  an  ir- 
regular patch  upon  the  part  of  a  trunk  from  which  the 
bark  has  been  stripped  off,  and  are  entirely  unprotected. 

The  cochenille  insects  (Coccidce,  LEACH),  so  called 
from  one  of  the  species  furnishing  the  well-known 
valuable  dye-stuff,  protect  their  eggs  in  a  still  more 

*  De  Gecr,  Mem.  sur  Ics  Insectes,  i-ii,  48,  51.  t  J.  R, 


88  INSECT    TRANSFORMATIONS. 

remarkable  manner.  The  mother  deposits  her  eggs 
under  her  body,  which  becomes  glued  to  the  spot;  she 
then  dies,  and  her  body  becomes  a  covering  for  the 
eggs.  In  this  state  the  insects  appear  on  the  bark 
of  trees  like  small  warts,  some  species  in  the  form  of  a 
boat,  some  kidney-shaped,  and  others  globular;  and, 
before  their  history  was  understood,  they  were  with 
some  plausibility  supposed  to  be  vegetable  galls,  — 
whence  they  were  termed  Gall  Insects  by  the  French. 
Though  the  mother  insect  is  seldom  larger  than  a 
peppercorn,  the  number  of  eggs  which  she  lays 
amounts  to  several  thousands,  and  in  fact  fills  the 
greater  portion  of  her  body.  Those  which  are  found 
on  our  green-house  plants,  and  which  are  the  pest 
of  the  grape-vines  in  the  neighbourhood  of  London, 
both  in  and  out  of  doors,  Secrete  a  sort  of  white 
silky  gum,  very  like  gossamer,  as  the  first  bed  of 
their  eggs.  Reaumur  could  not  discover  that  the 
mother  insect  was  furnished  with  any  organ  similar 
to  those  of  spiders  and  caterpillars  for  spinning  this 
gossamer;  and  in  an  allied  genus  (Dorthesia),  Kirby 
and  Spence  talk  of  it  as  £  wire-drawn  through  nu- 
merous pores  in  certain  oval  plates  in  the  skin.'* 
Having  minutely  observed,  during  several  successive 
summers,  some  thousands  of  the  female  cocci  found 
on  vines  in  the  open  air,  we  have  satisfied  ourselves 
that  this  cottony  matter  is  precisely  similar  to  the 
gluten  which  envelopes  the  eggs  of  most  insects; 
and  that  it  is  neither  spun  like  the  threads  of  cater- 
pillars, or  the  webs  of  spiders,  nor  wire-drawn 
through  numerous  pores,  —  but  is  simply  excluded 
along  with  the  eggs.  We  may  remark,  also,  that  the 
covering  formed  by  the  body  of  the  mother  coccus 
prevents  this  substance  from  drying,  as  the  webs  of 
spiders  do;  and,  consequently,  it  can  at  any  time  be 

*  Introd.  iii,  p.  183. 


EGGS    OF    THE    COCCI. 


89 


drawn  out  into  extended  threads,  by  detaching  a  few 
of  the  eggs  from  the  mass. 


Eggs  of  the  Coccus  covered  with  down,  and  with  the  bodies 
of  the  mothers. 

An  account,  which  appears  to  us  altogether  apo- 
cryphal, has  been  given  of  the  migrations  of  the 
species  which  produces  the  cochenille  (  Coccus  Cacti, 
LINN).  From  the  females  remaining  stationary,  it 
is  said,  their  numerous  progeny  would  not  find 
sufficient  nutriment  on  their  native  tree;  and  they 
are,  at  the  same  time,  so  delicate,  that  they  could  not 
travel  along  the  ground  from  one  plant  to  another; 


Magnified  cochenille  insects,  (Coccut  cacti).    «r,  Male.  6,  Female. 


90  INSECT    TRANSFORMATIONS. 

but  nature,  it  is  alleged,  provides  for  them  admirable 
means  of  emigration,  since,  at  the  period  of  their 
birth,  a  multitude  of  spiders  fasten  their  nets  to  the 
leaves  of  the  nopal,  and  along  these,  which  serve 
them  for  bridges,  the  young  cocci  emigrate  to  the 
adjacent  trees. *  We  have  little  doubt  that  this  story 
has  originated  in  the  inaccurate  observations  of  some 
fanciful  traveller,  who  mistook  the  threads  accidentally 
drawn  out  from  the  mass  of  eggs,  for  those  of  a 
spider. 

The  gossamer  envelope,  however,  which  we  have 
just  described  as  covering  the  eggs  of  the  coccus  that 
is  common  on  our  British  vines,  is  not  intended  as  a 
defence  against  the  cold  of  winter;  for  this  species 
hybernates,  according  to  Reaumur,  in  the  larva  state, 
though  we  have  frequently  searched  for  these  larvae 
in  vain  during  winter,  on  vines  where  they  swarmed 
in  myriads  during  summer.  But  the  British  species 
of  coccus  of  the  hawthorn,  &c,  on  account  of  which 
we  introduced  the  subject  here,  assuredly  hybernates 
in  the  egg  state;  and  may  be  seen  at  the  off-goings 
of  the  branchlets  in  an  oval  form,  like  that  of  a 
minute  wood-louse  (Omscws),  of  a  silvery  gray 
colour,  differing,  indeed,  'but  little  from  the  tint  of 
the  bark.  On  raising  up  with  the  point  of  a  pen- 
knife what  appeared  to  be  the  body  of  the  insect,  we 
found  that  it  was  hard,  dry,  and  dead, — the  mere 
skin,  in  a  word,  of  the  mother  coccus,  while  under- 
neath was  a  multitude  of  eggs  of  a  deep  orange 
colour.  It  is  worthy  of  notice,  also,  that  there  is, 
then,  no  envelope  of  gossamer,  though  there  is  mixed 
up  with  the  eggs  a  small  quantity  of  a  grayish  white 
powder,  which,  we  are  inclined  to  conjecture,  may 
be  the  dried  remains  of  it;  and,  the  more  so,  that 
Reaumur  figures  the  gossamer  as  abundant  in  the 
coccus  of  the  hawthorn.  Unfortunately  he  has  not 

*  St  Pierre,  Studies  of  Nature,  vol.  i. 


EGGS   OF    THE    COCCI. 


91 


mentioned  at  what  season  he  procured  these,  and  we 
have  no  means  of  ascertaining  whether  our  species  is 
the  same  with  his.* 


a  6  c,  Eggs  of  the  hawthorn  coccus,  covered  by  the  body  of  the 
dead  mother,  d,  one  of  these  magnified,  e,  a  section,  showing 
the  eggs  within. 

We  have  found  the  eggs  just  mentioned  most 
abundant  on  the  hawthorn  in  the  hedges  around 
London;  but  as  the  size,  the  colours,  and  the  forms 
of  the  crust  are  very  different,  there  can  be  no  doubt 
of  there  being  different  species  even  on  the  same 
tree.  '  In  July,  1812,' says  Rirby,  <I  saw  a  cur- 
rant-bush miserably  ravaged  by  a  species  of  coccus 
very  .much  resembling  the  coccus  of  the  vine.  The 
eggs  were  of  a  beautiful  pink,  and  enveloped  in  a 
large  mass  of  cotton-like  web,  which  could  be  drawn 
out  to  a  considerable  length. '|  From  the  manner  in 
which  this  justly  popular  author  speaks,  it  would  ap- 
pear he  had  not  elsewhere  met  with  this  coccus;  but 


*  J.R. 


t  Intr.  i,  197. 


92  INSECT    TRANSFORMATIONS. 

it  is  by  no  means  of  rare  occurrence,  and  may  be 
found  on  most  currant-bushes,  and  often  on  hawthorns, 
&c,  around  London.  The  envelope  of  the  eggs  is 
of  a  chestnut-brown  colour. 

A  much  more  singular  species  occurs  in  company 
with  the  preceding,  and  abounds  on  the  currant- 
bushes  at  Lee.  From  their  resemblance  to  the  form 
of  one  of  the  valves  of  a  mussel-shell,  Reaumur 
named  this  species  en  coquille  ( Coccus  conchiformis, 
GMELIN).  He  says,  it  imposed  upon  him  for  several 
years,  as  he  supposed  it  to  be  the  cocoon  of  some 
minute  insect  about  to  go  into  the  pupa  state;  but  he 
was  undeceived  by  finding  them  full  of  eggs.  We 
were  more  disposed,  at  first,  to  look  upon  them  as  a 
subcortical  fungus  (such  as  Cucurbitaria  Berbemdis, 
GREV.  or  Cryptosphceria  Pteridis,  So  WERE.),  for, 
during  the  winter,  when  we  first  observed  them,  they 
appeared  exactly  like  a  little  slip  of  the  bark  elevated 
by  the  growth  of  a  fungus  below  it.  Then  they  were 
so  crowded  on  some  branches,  that  not  a  hair's  breadth 
of  the  bark  remained  uncovered.  When,  however, 
we  found  these  minute  bark-like  scales  full  of  eggs,  we 
were  inclined  to  conjecture  that  they  had  been  depo- 
sited by  saw-flies  cutting  into  the  bark;  but  this  was 
instantly  disproved  by  removing  them,  and  finding  the 
bark  below  sound  and  uncut.  Reaumur  put  the 
matter  beyond  dispute  by  actually  hatching  the 
eggs,  when  insects  were  produced  similar  to  other 
cocci.  But  our  species,  found  on  the  currant-bush, 
seems  to  differ  from  his  of  the  elm,  not  in  form  and 
colour,  but  in  habit,  being  gregarious,  while  his  was 
subsolitary.* 

During  the  severe  frost  of  1829-30,  we  observed 
several  small  birds,  such  as  the  long-tailed  titmouse 
(Parus  caudatus),  and  the  gold-crested  wren  (Regu- 

*  J.  R. 


DEPOSITIONS    OF    EGGS.  93 

lus  cristatus,  RAY),  busily  pecking  the  eggs  of  the 
cocci  in  the  hedges.* 

The  resemblance  of  these  singular  insects  to  the 
wood-louse  (Oniscus),  which  is  not  properly  an  in- 
sect, but  a  crustaceous  animal,  may  be  traced  farther 
than  mere  external  appearance;  for  the  body  of  the 
mother,  in  the  latter,  also  becomes  a  covering  for 
the  egg,  though  she  does  not  die  immediately  after 
laying  as  the  coccus  does,  but  carries  her  eggs  under 
her  breast  in  small  four-valved  cells. 

One  of  the  most  easily  discovered  depositions  of 
eggs  during  the  winter  months  are  those  made  by 
various  species  of  spiders,  particularly  that  of  the 
large  garden-spider  (Epeira  diadema),  which  may 
be  found  in  the  angles  of  walls,  in  form  of  a  ball, 
about  the  size  of  a  cherry,  of  beautiful  yellow  silk, 
and  much  stronger  than  the  common  materials  of  the 
same  spider's  geometric  web.  This  substance  Reau- 
mur endeavoured  to  bring  into  use  as  a  substitute  for 
silk;  but  he  was  unsuccessful  in  procuring  it  in  quan- 
tity, owing  to  the  ferocious  habits  of  the  spiders, 
which  devoured  one  another  when  he  reared  them 
gregariously.  As  the  eggs  of  spiders  have  usually  a 
thin  soft  shell,  a  thick  warm  envelope  of  silk  is,  no 
doubt,  essential  to  their  weathering  the  colds  of  winter, 
notwithstanding  the  sheltered  corners  where  they  are 
usually  placed.  Some  species  weave  these  little  silk- 
en nests  in  a  very  elegant  form.  We  possess  one 
of  the  pyriform  shape  of  a  balloon,  the  texture  of 
which  is  close  and  netted  with  diagonal  meshes.  One, 
somewhat  in  form  of  a  drinking-glass,  is  figured  in 
Loudon's  Magazine  of  Natural  History,  as  having 
been  found  near  Wandsworth,  attached  to  the  stem 
of  a  rush  growing  in  water. 

There  was  a  deposition  of  eggs  at  the  bottom,  the 
rest  of  the  space  being  vacant.  De  Geer  describes 

*  J.  R. 


94 


INSECT    TRANSFORMATIONS. 


similar  spiders'  nests  attached  to  the  stems  of  grass;* 
and  we  once  found  a  large  one  of  an  elongated  shape, 
and  composed  of  very  white  silk,  en  a  spike  of  grass 
at  Compton-Basset,  Wiltshire.! 


Spiders'  nests. 

The  vapourer  ( Orgyia  antiqua,  OcnsENH.),a  com- 
mon moth,  takes,  advantage  of  the  warm  silken  enve- 
lope of  the  pupa-case,  from  which  she  has  escaped  a 
few  days  before,  to  form  a  bed  for  her  eggs.  In  our 
earlier  studies  of  insect  economy  we  were  inclined  to 
ascribe  to  accident  the  deposition  of  the  eggs  in  this 
particular  situation,  but  we  have  found  so  many  in- 
stances of  it  as  to  reject  the  explanation.  Swammer- 
dam  also  observes,  that  '  this  custom  of  fastening 
the  eggs  to  the  web  in  a  constant  method,  and 
by  the  immutable  law  of  nature,  is  so  peculiar  to 
this  species  of  insects,  that  I  have  never  obser- 
ved it  in  any  other  kind  whatsoever.  This  fe- 
male,' he  subjoins,  i  like  a  most  prudent  house- 
wife, never  leaves  her  habitation,  but  is  always 
fixing  her  eggs  to  the  surface  of  the  web  out  of 
which  she  has  herself  crept,  thus  affording  a  beau- 
tiful instance  of  industrious  housewifery. 'J  One 


De  Geer,  Mem.,  vol.  vii,  pp.  227  —  9. 
|  Swammerdam,  pt  ii,  page  7. 


t  J.  R. 


DEPOSITIONS    OF    EGGS.  95 

reason  for  this  is,  that  the  female  of  this  moth 
having  only  the  rudiments  of  wings,  a  peculiarity 
remarkable  in  several  other  moths,  she  cannot  shift 
so  readily  about.  But  whatever  may  be  the  real 
cause,  there  can  be  no  doubt  that  the  web  serves  to 
keep  the  eggs  warm  during  winter;  for  though  they 
are  placed  on  the  outside  of  the  web,  the  whole  is 
usually  under  some  projection  x>f  a  wall  or  arm  of  a 
tree,  and  the  non-conducting  property  of  the  silk, 
both  with  regard  to  heat  and  electricity,  must  be  of 
great  benefit  to  the  eggs  in  preserving  them  in  an 
equable  temperature,  and  of  course  promoting  their 
early  hatching. 


Vapourer  Moth.  (Orgyia  antiqua),  male  and  liemale,  the  latter 
without  wings  j  with  the  eggs  laid  upon  the  silken  cocoon  from 
which  the  mother  has  issued. 

We  cannot  better  conclude  these  imperfect  sketches 
of  the  hybernation  of  insect  eggs,  than  by  an  ac- 
count of  the  ingenious  experiments  made  by  Spal- 
lanzani  and  John  Hunter,  by  exposing  several  spe- 
cies of  these  to  great  degrees  of  cold  as  well  as 
of  heat.  It  results  from  these  experiments  that 
*  intense  cold,'  to  use  the  words  of  Spallanzani, 
6  does  not  destroy  the  eggs  of  insects.  The  year 
1709,  when  Fahrenheit's  thermometer  fell  to  1°, 
is  celebrated  for  its  rigour  and  its  fatal  effects  on 
plants  and  animals.  Who  can  believe,  exclaims 
Boerhaave,  that  the  severity  of  this  winter  did  not 
destroy  the  eggs  of  insects,  especially  those  exposed 
to  its  influence  in  the  open  fields,  on  the  naked 


96  INSECT    TRANSFORMATIONS. 

earth,  or  or  on  the  branches  of  trees  ?  Yet,  when  the 
spring  had  tempered  the  air,  these  eggs  produced  as 
they  usually  did  after  the  mildest  winters.  Since  that 
period  there  have  been  winters  more  severe.  In 
France,  during  December,  1788,  the  thermometer 
fell  considerably  lower,  and  in  several  other  tempe- 
rate European  climates. 

'  I  have  exposed  eggs  to  a  more  rigorous  trial 
than  the  winter  of  1709.  Those  of  several  insects, 
and  among  others  the  silk- worm,  moth,  and  elm 
butterfly  ( Vanessa  polychloros  ?)  were  enclosed  in  a 
glass  vessel  and  buried  five  hours  in  a  mixture  of  ice 
and  sal  gem  (rock  salt),  the  thermometer  fell  6° 
below  zero.  In  the  middle  of  the  following  spring, 
however,  caterpillars  came  from  all  the  eggs,  and 
at  the  same  time  as  from  those  that  had  suffered  no 
cold.  In  the  following  year,  I  submitted  them  to  an 
experiment  still  more  hazardous.  A  mixture  of  ice 
and  sal  gem  with  the  fuming  spirit  of  nitre  (Nitrate 
of  Ammonia),  reduced  the  thermometer  22°  below 
zero,  that  is  23°  lower  than  the  cold  of  1709. 
They  were  not  injured,  as  I  had  evident  proof  by 
their  being  hatched. 

'  Combining  all  these  facts,  we  conclude  that  cold 
is  less  noxious  to  germs  and  eggs,  than  to  animalcula 
and  insects.  Germs  in  general  can  support  2°  be- 
low zero;  whereas  of  animalcula  some  die  at  the 
freezing  point,  and  some  at  about  20°.  The  eggs 
of  many  insects  continue  fertile  after  being  subjected 
to  a  temperature  of  22°  below  zero,  while  insects 
themselves  die  at  16°  and  14°.  This  I  have  ascer- 
tained in  the  eggs  of  the  silk-\vorm  moth  and  of  the 
elm  butterfly;  and  although  there  are  caterpillars 
and  chrysalides  able  to  resist  great  cold,  I  have  uni- 
formly found  it  to  be  in  a  less  degree  than  what  can 
be  resisted  by  their  eggs.  What  can  be  the  cause  of 
so  great  a  difference?  Insects  killed  at  16°  and  14° 


EFFECTS  OF  COLD  UPON  EGGS.        97 

are  so  penetrated  and  frozen  by  the  cold,  that  their 
members  do  not  yield  to  the  pressure  of  the  finger, 
and  seem  perfect  ice  under  the  knife.  This  does 
not  happen  to  eggs,  though  subjected  to  cold  of  much 
greater  intensity.  Their  contents  remain  fluid,  even 
at  the  greatest  cold,  as  may  be  seen  by  crushing  them 
with  the  nail.  Perhaps  this  is  derived  from  constitu- 
ent spirituous  or  oleaginous  parts,  or  from  some  prin- 
ciple adapted  to  abate  the  power  of  cold.*  If  eggs 
do  not  freeze,  it  is  probable  the  included  embryos  do 
not  freeze.  '  Is  there  anything  wonderful,  therefore, 
that  they  then  survive  cold  which  is  fatal  to  them 
when  produced  ?  *  Probably  for  the  same  reason  (and 
I  see  no  objection  that  can  apply),  animalcula,  con- 
centrated in  the  germ,  can  support  a  degree  of  cold 
they  are  incapable  of  when  developed. 

*  As  the   temperature    of  freezing   still  retains   a 
portion  of  heat,  why,  it  may  be  asked,  should  it  not 
develope  the  germs  of  the  most  minute  animalcula? 
Had  we  never  seen  any  eggs  hatched  but  those  of 
birds,  which  require  104°,  we  should  have  concluded 
that   all  others  require  the  same.      A   little  initiation 
into  the  study  of  minute  animals  teaches  how  many 
kinds  produce  at  a  temperature  infinitely  less.     Such 
are  the  eggs  of  butterflies  and  many  other  insects,  of 
frogs,  lizards,  tortoises,  down  to  some,  as  those  of 
toads,  which  I  have  seen  produce  at  45°.      If  these 
eggs  hatch  at  59°  less  than  is  required  by  those  of 
birds,  what  repugnance  will  there  be  to  suppose  that 
at   13°  less,  or  the  freezing  point,  the  eggs  of  other 
animals  may  be  hatched  ?  Nor  should  it  surprise  me 
to  be  told  of  animals  whose  eggs  would  produce  at 
much  greater  cold,  after  knowing  that  there  are  plants, 
beings   so   similar   to   animals,  and   many   of  them, 

*  In  plain  language,  Spallanzani  did  not  know  what  to 
make  of  the  facts. 

9 


98  INSECT   TRANSFORMATIONS. 

which  amidst  the  rigours  of  winter  flourish  and  fruc- 
tify,'* 

It  is  remarked  by  John  Hunter  that  an  egg  will 
freeze  by  a  great  degree  of  cold;  at  the  same  time 
there  seems  to  be  a  living  principle  which  enables  it  to 
support  cold  without  destruction,  and  when  once  that 
principle  is  destroyed,  cold  more  easily  operates.  An 
egg  was  thus  frozen  by  the  cold  of  zero;  after  thaw- 
ing and  again  exposing  it  to  the  same  degree  of  cold, 
it  froze  seven  minutes  and  a  half  sooner.  A  new-laid 
egg  took  an  hour  to  freeze  in  15°  and  17°,  but  when 
thawed,  it  froze  at  25°  in  half  the  time.| 

The  principle  of  vitality,  therefore,  whatever  may  be 
the  cause,  is  evidently  less  easily  destroyed  in  the  egg 
state  than  in  the  perfect  animal;  and  therefore  the 
inference  that  a  rigorous  winter  promises  a  diminution 
of  insects  in  the  summer  succeeding  commonly  proves 
erroneous.  On  the  contrary,  recorded  facts  prove 
that  they  are  sometimes  even  more  abundant  than 
usual  after  severe  frosts.  During  the  present  spring 
of  1830,  accordingly,  notwithstanding  the  severe  frosts 
of  the  preceding  winter,  we  have  observed  a  much 
greater  number  of  insects,  even  of  the  smaller  and 
more  delicate  kinds  (Jlleyrodes,  Corethra,  Jllucitay 
&c,)  as  well  as  of  larvae,  both  those  just  hatched,  and 
those  which  have  lived  through  the  winter,  than  last 
year,  when  the  frost  was  not  so  severe.  We  were 
particularly  struck  with  the  larvee  of  some  small 
tipula  (Boletophila?),  which  we  found  in  abundance 
in  Birch  Wood,  Kent,  feeding  on  a  fungus  (Boletus 
fomentarius,  FRIES),  and  which  were  so  beautifully 
transparent  and  soft,  that  we  could  not  understand 
how  they  had  escaped  being  frozen.  It  is  not  a 
little  remarkable,  in  connexion  with  this,  that  the 

*  Spallanzani's  Tracts,  transl.   by  Dalyell,  vol.  i,  p.  63. 
t  Hunter  on  the  Animal  Economy. 


EFFECTS   OF    COLD    UPON    INSECTS.  99 

migratory  birds  seem  to  have  been  aware  of  this  abun- 
dance of  insects  by  their  appearing  earlier  than  usual. 
We  saw  a  pair  of  nightingales  at  Greenhithe  on  the 
21st  of  March,  and  a  number  of  swallows  the  same 
week  at  Lee,  —  which  is  two  or  three  weeks  before 
their  average  time.* 

*  J.  R. 


CHAPTER  V. 

Hatching  of  Insect  Eggs. 

THE  contents  of  an  egg  principally  consist  of 
nutriment  adapted  to  the  different  parts  of  the 
germ  which  it  contains  —  the  yolk  for  nourishing 
the  soft  parts;  tfce  white,  for  the  blood  and  other 
fluids;  and  the  shell,  for  the  bones.  In  the  case  of 
insects,  as  well  as  of  birds,  fishes,  and  reptiles,  the 
embryo  is  placed  in  the  most  advantageous  posi- 
tion for  partaking  of  the  repast,  —  namely,  in  a  par- 
ticular corner  where  it  may  breathe  fresh  air  always 
communicated  to  the  chamber  of  the  egg  by  ven- 
tilatory  passages  in  the  shell;  if  these  be  shut  up, 
by  covering  the  egg  with  grease,  varnish,  or  chalk, 
it  is  suffocated  and  dies.  „  In  the  case  of  birds, 
according  to  Malphigi  and  the  older  physiologists,* 
the  rudiment  of  the  chick,  while  still  a  minute  point, 
is  lodged  on  the  film  that  envelopes  the  yolk,  near  the 
centre  of  the  egg;  and,  —  as  the  floating  wick  of  a 
mariner's  lamp  is  constantly  preserved  upon  a  level 
with  the  surface  by  the  mobility  of  the  slings  and  the 
weight  of  the  oil-vessel  tending  downwards,  how- 
ever the  ship  move,  —  there  is  an  ingenious  natural 
mechanism,  which  prevents  the  embryo  chick  from 
being  upset  when  the  egg  is  stirred.  The  yolk  is 
sustained  by  two  membranous  ribbons,  visible  at  the 
aperture  of  the  egg,  and  fastening  it  on  each  side  to 
the  common  membrane  glued  to  the  shell.  These 
suspensory  bands  being  fixed  above  the  centre  of  the 

*  Malpighi,  de  Ovo  incubato  ,  Leeuwenhoeck,  Epist.  phys. 
xl  ;  and  Harvey,  in  Willoughby's  Ornithol.  c.  iii. 


HATCHING   OF   EGGS.  101 

yolk,  of  course  the  mere  weighty  part  always  de- 
scends, in  every  position  of  the  egg,  as  far  as  they 
will  permit,  and  the  chick  being  thence  prevented 
from  sliding  down,  nourishes  itself  in  security. 

We  cannot,  on  account  of  their  minuteness,  as  Cer- 
tain whether  there  is  any  similar  mechanical  contriv- 
ance in  the  eggs  of  insects  ;  but  we  have  in  several 
instances  distinctly  observed  the  speck  where  the  em- 
bryo insect  was  placed  just  within  the  shell  of  the 
egg.  In  order  to  stimulate  it  to  feast  and  fatten  on 
the  good  things  stored  up  in  his  egg  shell  chamber, 
it  appears  that  a  certain  degree  of  heat  is  indispensa- 
bly requisite;  for  cold,  though  it  does  not  usually,  as 
we  have  seen,  kill  the  embryo,  almost  always  renders 
it  torpid.  But  the  stimulus  of  heat  produces  activity 
in  the  living  principle,  causes  the  embryo  to  devour 
all  the  nutritive  contents  of  the  egg,  and  thence  to  in- 
crease proportionably  in  size.  It  is  worthy  of  remark, 
however,  that  the  stimulus  of  light,  contrary  to  that  of 
heat,  acts  unfavourably  upon  the  hatching  of  eggs. 
Both  of  these  positions  may  be  illustrated  by  nume- 
rous facts  and  experiments. 

Most  birds,  so  far  as  has  been  ascertained,  supply 
the  heat  necessary  for  hatching  their  eggs  by  sitting 
constantly  upon  them  during  a  certain  number  of 
days  ;  but  reptiles,  such  as  the  crocodile,  bury  their 
eggs  in  the  warm  sand  upon  the  banks  of  rivers. 
Insects,  again,  seldom,  if  ever,  sit  upon  their  eggs,  as 
birds  do,  in  order  to  hatch  them.  This,  indeed, 
would  be  impossible,  as  the  greater  number  of  insects 
die  in  a  few  days  after  depositing  their  eggs,  the  con- 
tinuation of  the  species  being  apparently  their  only 
business  in  their  last  or  perfect  stage  ;  since,  as  they 
then  generally  cease  to  feedV,  they  cannot  possibly  live 
long.  A  few  instances,  however,  have  been  observ- 
ed, of  insects  performing  something  very  similar  to  the 
9* 


102  INSECT    TRANSFORMATIONS. 

incubation  of  birds,  though  we  have  the  high  authority 
of  Fabricius,  that  <  insects  never  sit  upon  their  eggs.7* 
Upon  the  incontestable  statements  of  two  distin- 
guished observers  of  insects,  Frischf  and  De  Geer, 
the  female  of  the  common  earwig  (Forficula  auricula- 
ria,  LINN.)  sits  upon  her  eggs.  This  circumstance, 
however,  seems  to  have  escaped  the  notice  of  other 
naturalists,  though  her  attentions  to  her  young  ones 
is  often  witnessed.  De  Geer  discovered  a  female  ear- 
wig in  the  beginning  of  April  under  some  stones,  and 
brooding  over  a  number  of  eggs,  of  whose  safety  she 
appeared  to  be  not  a  little  jealous.  In  order  to  study 
her  proceedings  the  better,  he  placed  her  in  a  nurse- 
box  filled  with  fresh  earth,  and  scattered  the  eggs  in 
it  at  random.  She  was  not  long,  however4,  in  collect- 
ing them  with  all  care  into  one  spot,  carrying  them 
one  by  one  in  her  mandibles,  and  placing  herself  over 
them.  She  never  left  them  for  a  moment,  sitting  as 
assiduously  as  a  bird  does  while  hatching.  In  about 
five  or  six  weeks  the  grubs  were  hatched,  and  were 
then  of  a  whitish  colour. J  At  another  time,  in  the 
beginning  of  June,  De  Geer  found  under  a  stone  a 
female  earwig  accompanied  with  a  numerous  brood  of 
young,  to  all  appearance  newly  hatched,  and  nestling 
under  their  mother  like  chickens  under  alien.  These 
he  likewise  placed  in  a  nurse-box  with  fresh  earth  ; 
but  instead  of  burrowing  into  the  mould,  as  he  had 
expected,  they  crowded  under  the  bosom  and  between 
the  legs  of  their  mother,  who  remained  quiet  and  evi- 
dently pleased,  suffering  them  to  continue  there  for 
an  hour  or  more  at  a  time.  He  fed  both  this  brood 
and  the  one  first  mentioned  with  bits  of  ripe  apple  ; 
and  perceived  that  they  grew  from  day  to  day,  and 

*  Fabricius,  Philosoph.  EntOmoI.  Ixxvi. 
f  Insecten  in  Deutschland,  4to,  1766. 
t  De  Geer,  Mem.,  vol.  Hi,  p.  548. 


HATCHING    OF     EGGS.  103 

cast  their  skins,  as  caterpillars  do,  more  than  once. 
The  mother  did  not  live  long,  probably  in  consequence 
of  confinement ;  and  her  progeny  devoured  nearly  the 
whole  of  her  body,  as  they  also  did  the  bodies  of  their 
brethren,  when  any  of  these  chanced  .to  die.  We 
may  remark,  in  passing,  that  it  is  an  unfounded  popular 
prejudice  that  earwigs  get  into  the  brain  by  creeping 
into  the  ear  ;  for  though,  from  being  night  insects, 
and  disliking  exposure  to  the  light,  they  may,  by 
chance,  attempt  to  take  shelter  in  the  ear,  the  dis- 
agreeable odour  of  the  wax  will  soon  drive  them  out: 
at  all  events  they  could  never  get  farther  than  the 
drum,  which  completely  shuts  the  passage  to  the  brain. 
We  have  known,  indeed,  a  small  beetle,  get  into  the 
ear;  but  it  did  no  further  injury  than  produce  a 
strange  tingling  sensation  by  crawling  about  the 
drum,  and  soon  made  its  exit.*  A  little  red  insect 
(the  harvest  bug?)  sometimes  gets  into  the  ear  in 
bed,  and  produces  wonderful  commotion,  but  no  real 
injury. 


Drum  of  the  ear,  showing  that  there  is  no  passage  through  it  to 
the  brain. 

Kirby  and  Spence  are  inclined  to  infer  that  a  tree 
bug   (Jlcanthosotnci  grisea,  STEPHENS)   may  also  sit 

*  J.  R. 


104  INSECT    TRANSFORMATIONS. 

upon  its  eggs,*  because  De  Geer  found  a  mother  of 
this  species  surrounded  with  a  brood  of  thirty  or  forty 
young  ones  following  her  as  chickens  follow  a  hen. 
She  never  leaves  her  family;  but  as  soon  as  she 
moves,  all  the  young  ones  closely  follow,  and  assem- 
ble around  her  in  a  cluster  wherever  she  makes  a 
halt.  De  Geer  once  cut  a  branch  of  birch,  upon 
which  a  family  of  these  bugs  had  assembled,  and  the 
mother  showed  every  symptom  of  fear  and  distress. 
Had  she  not  had  a  family  to  protect,  she  would  have 
taken  immediate  flight;  but  instead  of  this,  she  kept 
beating  her  wings  rapidly  and  incessantly,  and  never 
stirred  from  her  young.  But  even  all  this,  affec- 
tionately maternal  as  it  must  be  considered,  is  far 
from  authorizing  the  conclusion  that  she  sits  upon 
her  eggs  ;  though  it  is  certain  she  must  remain  near 
them  till  they  are  hatched,  unless  she  belong  to  those 
mentioned  by  Busch  as  ovo-viviparous.j" 

One  of  the  most  common  instances  of  something 
similar  to  birds  hatching  their  eggs  occurs  in  several 
species  of  spiders,  which  may  be  seen  sitting  near 
or  upon  the  silken  bag  in  which  they  have  inclosed 
their  eggs.  Many  of  these  mothers,  however,  die 
before  their  young  are  hatched,  —  all  of  them,  per- 
haps, when  the  eggs  are  laid  late  in  autumn.  During 
the  winter  of  1829-30,  we  watched  a  considerable 
number  of  the  geometric  spiders  (Epeirce)  brooding 
over  their  eggs  for  several  weeks;  but  though  the 
weather  before  Christmas  was  little  more  than  an 
average  degree  of  coldness,  every  one  of  them  died, 
some  living  a  longer  time,  and  others  a  shorter.  J  But 
this  is  not  the  case  with  a  very  common  wandering 
spider  called  by  Dr  Lister  the  wolf  (Lycosa  saccata, 
LATR.),  and  first  observed,  we  believe,  by  the  cele- 
brated Harvey.^  '  In  order,'  says  Swammerdam,  *  to 

*  Intro,  i,  358,  and  iii,  101. 

t  Schneider,  Europaische  Schmetterlinge,  i,  206.      £  J.  R. 

§  Harvey,  De  Generatione. 


HATCHING    OF    EGGS.  105 

hatch  her  eggs  the  better,  she  carries  them  about  as 
it  were  in  a  case,  with  wonderful  solicitude  and  affec- 
tion ;  insomuch,  that  when  the  skin  forming  this  case, 
which  hangs  to  the  hinder  part  of  her  body,  is  by 
any  accident  broken  off,  the  little  insect  seeks  after 
it  with  as  much  earnestness  and  industry  as  a  hen  for 
her  lost  chickens,  and  when  found  fastens  it  again 
to  its  place  with  the  greatest  marks  of  joy.'* 

Bonnet  has  given  a  more  detailed  account  of  the 
manners  of  ttys  spider,  which,  though  no  less  fierce 
and  ferocious  in  aspect  than  her  congeners,  manifests 
an  extraordinary  change  of  mien  when  forcibly  depriv- 
ed of  her  eggs.  Then  she  instantly  appears  tame, 
stops  to  look  around  her,  and  begins  to  walk  at  a  slow 
pace,  and  search  on  every  side  for  what  she  has  lost, 
nor  will  she  even  fly  when  one  threatens  to  seize  her. 
But  should  the  experimenter,  moved  with  compassion, 
restore  her  bag  of  eggs,  she  catches  it  up  with  all  haste, 
and  darts  away  in  a  moment ;  or,  when  left  undisturb- 
ed, will  leisurely  attach  it  again  to  her  body. 

'  With  a  view,'  continues  Bonnet,  '  to  put  this 
singular  attachment  to  a  novel  test,  I  one  day  threw 
a  spider  with  her  eggs  into  the  pit-fall  of  an  ant-lion 
(Myrmelion  formicariwn) ."\  The  spider  endeavoured 
to  escape,  and  was  eagerly  remounting  the  side  of  the 
pit,  when  I  again  tumbled  her  to  the  bottom,  and  the 
ant-lion,  more  nimble  than  the  first  time,  seized  the  bag 
of  eggs  with  its  mandibles,  and  attempted  to  drag  it 
under  the  sand.  The  spider,  on  the  other  hand,  made 
the  most  strenuous  efforts  to  keep  her  hold,  and  strug- 
gled hard  to  defeat  the  aim  of  the  concealed  depreda- 
tor ;  but  the  gum  which  fastened  her  bag,  not  being 
calculated  to  withstand  such  violence,  at  length  gave 
way,  and  the  ant-lion  was  about  to  carry  off  the  prize 

*  Book  of  Nature,  pt  i,  p.  24. 
t  See  Insect  Architecture,  p.  209. 


106  INSECT    TRANSFORMATIONS. 

in  triumph.  The  spider,  however,  instantly  regained 
it  with  her  mandibles,  and  redoubled  her  endeavours 
to  snatch  the  bag  from  her  enemy  ;  but  her  efforts 
were  vain,  for  the  ant-lion,  being  the  stronger,  suc- 
ceeded in  dragging  it  under  the  sand.  The  unfortu- 
nate mother,  now  robbed  of  her  eggs,  might  have  at  least 
saved  her  own  life,  as  she  could  easily  have  escaped 
out  of  the  pit-fall  ;  but,  wonderful  to  tell,  she  chose 
rather  to  be  buried  alive  along  with  her  eggs.  As  the 
sand  concealed  from  my  view  what  was  passing  below, 
I  laid  hold  of  the  spider,  leaving  the  bag  in  the  power 
of  the  ant-lion.  But  the  affectionate  mother,  de- 
prived of  her  bag,  would  not  quit  the  spot  where  she 
had  lost  them,  though  I  repeatedly  pushed  her  with  a 
twig.  Life  itself  seemed  to  have  become  a  burden 
to  her  since  all  her  hopes  and  pleasures  were  gone  for 
ever.'* 

That  some  portion  of  heat  may  be  communicated 
to  the  eggs  of  the  spider,  which  are  thus  carried  so 
assiduously  under  her  body,  is  highly  probable  ;  and 
it  is  also,  no  doubt,  advantageous  to  the  young,  when 
hatched,  to  have  the  assistance  of  their  mother  to  open 
the  bag  for  them,  as  was  remarked  by  De  Geer;| 
'  without  which,'  says  Kirby  and  Spence,  c  they 
could  never  escape. 'J  But  that  neither  of  these  are 
indispensable  conditions  we  have  ascertained  by  re- 
peated experiments.  We  have  taken  a  considerable 
number  of  these  egg-bags  from  their  mothers,  and 
put  them  under  inverted  wine-glasses  and  into  pill- 
boxes, and  in  every  instance  the  young  have  been 
duly  hatched,  and  made  their  way  without  assistance 
out  of  the  bag.  In  all  these  experiments,  the  young 
spiders  joined  in  concert  in  making  a  web  across  their 
prison  ;  a  circumstance  at  variance  with  the  assertion 

*  Bonnet,  (Euvres,  vol.  ii,  p.  435. 
t  De  Geer,  Mem.  vol.  vii,  p.  194. 
J  Introd.  i,  p.  361. 


HATCHING   OF     EGGS.  107 

copied  from  Lister  into  most  subsequent  works  on 
natural  history,  that  this  species  never  spins  a  web. 
They  might  not  indeed  have  done  so  if  they  had  been 
left  at  liberty.* 

A  spider  of  the  same  species,  which  Bonnet  kept 
under  an  inverted  glass,  at  first  was  so  exceedingly 
attached  to  her  bag  of  eggs,  that  he  could  riot  beat 
her  away  from  it  after  it  was  detached.  '  By  and 
by,'  he  continues,  c  I  observed  with  surprise  that  she 
had  abandoned  and  kept  aloof  from  the  very  bag 
which  she  had  previously  defended  with  so  much  cou- 
rage and  address;  and  I  marvelled  still  more  to  see 
her  run  away  from  it  when  I  placed  it  near  her.  I 
remarked  at  the  same  time  that  she  had  become  less 
agile,  seemingly  in  consequence  of  sickness.  By 
more  close  observation,  I  discovered  that  several  of 
the  young  ones  were  hatched,  and  their  numbers 
increased  by  degrees,  while  all  ran  towards  their 
mother  and  climbed  upon  her  body.  Some  placed 
themselves  on  her  back,  some  on  her  head,  and  some 
on  her  limbs,  so  that  she  was  literally  covered  with 
them,  and  appeared  to  bend  under  the  weight,  not  so 
much  from  being  over-loaded,  as  from  her  feeble  con- 
dition ;  and  indeed  she  soon  afterwards  died.  The 
young  spiders  remained  in  a  group  upon  the  body 
of  their  mother,  which  they  did  not  abandon  for  some 
time,  and  for  the  purpose,  as  I  was  half  inclined 
(pardon  the  odious  supposition)  to  think,  of  sucking 
the  juices  of  her  body.'f 

In  order  to  prove  whether  a  spider  of  this  species 
could  distinguish  her  own  egg-bag  from  that  of  a 
stranger,  we  interchanged  the  bags  of  two  individuals, 
which  we  had  put  under  inverted  wine-glasses  ;  but 
both  manifested  great  uneasiness,  and  would  not  touch 
the  strange  bags.  We  then  introduced  one  of  the 
mothers  into  the  glass  containing  her  eggs  and  the 

*  J.  R.  t  Bonnet,  GEuvres,  vol.  ii,  p.  440. 


108  INSECT    TRANSFORMATIONS. 

other  spider;  but  even  then  she  did  not  take  to  them, 
which  we  attributed  to  the  presence  of  the  other,  as 
all  spiders  nourish  mutual  enmity.  Upon  removing 
the  stranger,  however,  she  showed  the  same  indiffer- 
ence to  her  eggs  as  before,  and  we  concluded  that, 
after  having  lost  sight  of  them  for  a  short  time,  she 
was  no  longer  able  to  recognize  them.* 

A  more  extraordinary  method  of  hatching  eggs  oc- 
curs in  several  insects,  thence  termed  ovo-viviparous, 
which  retain  the  eggs  within  their  bodies  till  they  are 
hatched;  and  in  this  way  they  appear,  like  larger  ani- 
mals, to  produce  young  instead  of  eggs.  We  do  not 
here  allude  to  the  cochenille  insects  formerly  mention- 
ed; for  though  these  cover  their  eggs  with  their 
bodies,  it  is  after  they  are  laid  and  imbedded  in  gos- 
samer. Neither  can  these  singular  insects  be  proper- 
ly said  to  sit  upon  their  eggs,  inasmuch  as  the  mother 
always  dies  when  she  has  finished  laying. 

The  gufTer  (Blennius  ovo-mviparus,  LACEPEDE), 
a  British  sea-fish,  common  under  stones  at  low-water 
mark,  affords  an  instance  of  this  singular  mode  of  the 
eggs  being  hatched  in  the  body  of  the  mother;  and  it 
is  remarkable  that  when  the  young  are  ready  to 
appear,  she  leaves  her  usual  haunts  on  the  coast,  and 
goes  farther  out  to  sea,  that  they  may  be  out  of  the 
reach  of  their  natural  enemies. |  Our  common  viper 
(Coluber  berus,  LINN.)  is  also  ovo-viviparous,  as  are 
several  other  reptiles;  though  it  is  an  exception  to  the 
general  rule  in  this  class.  We  caught  a  female  of  the 
nimble  lizard  (Lacerta  agilis,  LINN.)  on  a  heath 
near  Sorn,  Ayrshire,  in  July,  and  kept  it  for  some  time 
under  a  glass,  where  it  produced  six  young  ones;  but 
in  consequence  of  improper  food,  or  of  confinement, 
they  all  soon  died.J  This  lizard  is  said  to  be  some- 
times oviparous.  The  observations  also  of  the  elder 

*  J,  R.         t  Lacepede,  Poissoris,  ii,  p.  497.         $  J.  R. 


OVO-VIVIPAROUS    INSECTS.  109 

naturalists  with  respect  to  the  scorpion's  being  ovo- 
viviparous,  have  been  recently  verified  by  Leon 
Duibur,*  a  living  French  naturalist,  distinguished  for 
acuteness  and  accuracy. 

In  the  case  of  insects,  it  was  first  discovered  by 
Redi,  the  father  of  experimental  entomology,  that, 
though  the  greater  number  of  flies  lay  eggs,  some 
also  bring  forth  their  young  alive;  and  he  was  thence 
led  to  put  the  question,  whether  such  flies,  under  dif- 
ferent circumstances  of  temperature,  do  not  sometimes 
produce  young,  and  at  other  times  deposit  eggs."f  He 
might  as  well,  says  R  aumur,  have  asked  whether, 
in  certain  circumstances,  a  hen,  instead  of  laying 
eggs,  should  bring  forth  chickens.  The  fact,  on  the 
contrary,  has  been  ascertained  by  Rf  aumur,  and  re- 
cently confirmed  by  Dufour,J  that  the  ovo- viviparous 
insects  are  furnished  with  an  abdominal  pouch,  in  which 
the  eggs  are  deposited  by  the  mother  previous  to  their 
being  hatched.  In  this  respect  they  afford  a  striking 
analogy  with  the  kangaroo,  the  opossum,  and  other 
marsupial  quadrupeds,  which  are  furnished  with  a  simi- 
lar pouch  for  protecting  their  young  in  the  first  stage 
of  their  existence.  One  of  our  most  common  flies 
exemplifies  this. 

It  may  not  have  occurred  to  many  of  our  readers 
that  there  are  more  sorts  than  one  of  the  large  flies 
usually  called  blow-flies  and  flesh-flies.  One  of  these, 
distinguished  by  its  brilliant  shining  green  colour  and 
black  legs  (Musca  Ccesar,  LINN.),  we  have  adverted 
to§  in  recounting  the  experiments  of  Redi;  another, 
frequently  called  the  blue-bottle  (Musca  vomitoria, 
LINN.),  is  easily  distinguished  by  the  abdomen  being 
of  a  shining  blue,  the  shoulders  black,  and  the  forehead 
fox-coloured.  The  insect,  however,  to  which  we  wish  to 
call  attention  at  present,  though  nearly  the  size  of  the 

*  Nouv.  Diet.  d'Hist.  Nat.,xxx,  426. 

t  Redi,  Esperienze  intorno  alia  Gen.  degP  Insetti,  4to,  1668. 
t  Annales  des  Sciences  Naturelles.  §  Page  3. 

TOL.    VI.  10 


110  INSECT    TRANSFORMATIONS. 

blue -bottle,  rather  longer  and  more  slender,  and  black, 
with  lighter  stripes  on  the  shoulders,  is  not  blue  in  the 
abdomen,  but  grayish  black,  and  all  over  chequered 
with  squares  of  a  lighter  colour.  This  chequered  blow- 
fly (Sarcophaga  carnaria,  MEIGEN)  does  not  even 
belong  to  the  same  genus  as  the  preceding,  and  differs 
from  it  in  the  remarkable  circumstance  of  hatching 
its  eggs  in  an  abdominal  pouch,  and  instead  of  eggs 
depositing  maggots  upon  dead  carcasses.  The  eggs 
of  all  the  flesh  flies  are  in  sultry  weather  hatched  with 
great  rapidity;  but  in  the  case  of  the  chequered  blow- 
fly, nature  has  provided  the  means  of  still  more  rapid 
destruction  for  removing  the  offensive  parts  of  carcasses. 
The  arrangement  of  the  numerous  minute  Iarva3  in  the 
pouch  is  very  remarkable,  and  resembles  the  coil  of  a 
watch-spring  or  a  roll  of  ribbon.  R  aumur  had  the 
patience  and  perseverance  to  uncoil  this  multitudinous 
assemblage  of  flies  in  embryo,  and  found  it  about  two 
inches  and  a  half  in  length,  though  the  body  of  the 
mother-fly  herself  was  only  about  one-third  of  an  inch, 


A,  the  chequered  blnw-fly  B,  the  abdomen  of  the  chequered 
Mow-fly,  opened  and  magnified,  showing  the  coil  of  young  larva1. 
C,  the  coil  of  larvqp  partly  unwound. 


OVO-VIVIPAROUS    INSECTS.  1  1  1 

and  he  computed  that  there  were  about  20,000  young 
in  the  coil.*  When  this  extraordinary  fecundity  is 
considered,  we  need  not  wonder  at  the  countless  swarms 
which  appear  as  if  by  magic  upon  a  joint  of  meat  du- 
ring hot  weather. 

Like  most  female  insects,  the  mother-fly  dies  in  a 
few  days  after  giving  birth  to  her  numerous  brood; 
but,  unlike  the  oviparous  flies,  she  seems  to  take  a 
considerable  time  to  deposit  the  whole.  It  would  be 
impossible  indeed  for  her  pouch  to  contain  the  larvae 
if  they  were  all  hatched  at  the  same  time;  and  there- 
fore it  has  been  so  ordered  by  Providence  that  they 
should  arrive  at  maturity  in  succession.  From  the 
early  death  of  the  mother,  R  aumur  conjectured  that 
they  did  not  scruple  to  eat  their  way  through  her 
bowels;  but  he  disproved  his  supposition  by  a  most 
decisive  experiment.  He  took  a  fly  which  had  already 
deposited  a  few  larvae,  and  closed  the  natural  opening 
of  the  pouch  with  sealing-wax,  so  that  it  was  impossi- 
ble any  more  could  make  their  exit  there.  The  mother 
lived  several  days  longer  than  she  would  have  done, 
had  she  been  left  at  liberty  to  produce  her  young;  but 
not  one  of  them  attempted  to  force  a  passage,  after 
being  shut  up  for  ten  days. 

Another  large  gray  fly  with  brick-red  eyes  (species 


A,  large  gray  blow-fly,  with  the  abdomen  opened,  showing  the  young 
maggots.  B,  breathing  apparatus  of  the  maggot  of  a  large  gray  blow- 
fly- 

*  Reaumur,  Mem.  iv,  417. 


112  INSECT   TRANSFORMATIONS. 

not  ascertained)  was  discovered  by  Rt'aumur  to  be  ovo- 
viviparous;  but  the  embryo  flies  were  not  arranged  in 
the  pouch  in  the  same  spiral  form  as  the  preceding, but 
longitudinally.  These  did  not  appear  to  be  quite  so 
numerous;  and  they  had  a  peculiar  breathing  appara- 
tus, which,  when  shut,  as  it  could  be  at  pleasure,  ap- 
peared in  the  form  of  a  crown. 

Amongst  several  other  ovo-viviparous  flies  discovered 
by  R  aumur,  there  was  a  very  minute  tipulidan  gnat 
(species  not  ascertained)  with  a  jet-black  body,  white 
wings,  and  beaded  antemue,  not  larger  than  the  head 
of  an  ordinary  pin,  which  was  bred  in  great  numbers 
from  some  cows'  dung  put  into  one  of  his  nurse-boxes 
for  another  purpose.  He  justly  remarks  upon  this  cir- 
cumstance, that  'the  minute  and  the  grand  are  nothing, 
or  rather  are  the  same,  to  the  Author  of  nature.' 

The  numerous  genus  Aphis  presents  the  singular 
anomaly  of  producing  eggs  in  the  autumn  and  living 
young  during  summer,  and,  as  Curtis  tells  us,  even 
during  winter  in  green-houses.  De  Geer,  however, 
ascertained  that  it  was  not  the  same  individual  aphides 
which  at  one  season  produced  young  and  at  another 
eggs,  but  different  generations.*  By  a  series  of  very 
careful  and  troublesome  experiments  Bonnet  also  ascer- 
tained the  curious  fact,  that  in  three  months  nine  gene- 
rations of  these  insects  may  be  produced  in  succes- 
sion, though  the  males  be  rigorously  excluded  from  the 
nurse-boxes  where  the  females  are  isolated.  In  fact 
all  the  aphides  produced  in  spring  from  the  eggs  laid 
in  autumn  appear  to  be  females;  and  no  males  are  pro- 
duced till  the  end  of  summer,  a  short  time  before  the 
eggs  are  deposited  for  winter.  Among  both  males  and 
females  are  some  with  and  some  without  wings, — the 
nature  of  which  distinction  does  not  appear  to  be  yet 
ascertained. 

*  De  Geer,  Mem.  des  Insectes,  iii,  70. 


EGGS    GF    APHIDES.  1  13 

Bonnet,  however,  whose  opinion  is  entitled  to 
considerable  authority,  seems  to  think  that  the  eggs  of 
aphides  which  are  destined  to  survive  the  winter  are 
very  different  from  other  eggs;  and  he  supposes  that  the 
insect,  in  a  state  nearly  perfect,  quits  the  body  of  its 
mother  in  that  covering  which  shelters  it  from  the  cold 
in  winter,  and  that  it  is  not,  as  other  germs  are  in  the 
egg,  surrounded  by  food,  by  means  of  which  it  is  de- 
veloped and  supported.  It  is  nothing  more,  he  con- 
jectures, than  an  asylum  of  which  the  aphides  ap- 
pearing at  another  season  have  no  need;  and  it  is  for 
this  reason  that  some  are  produced  naked  and  others 
enveloped  in  a  covering.  If  this  be  correct,  the  mo- 
thers are  not  then  truly  oviparous,  even  in  autumn, 
when  they  deposit  these  pseudo-eggs;  since  their  young 
are  almost  as  perfect  as  they  ever  will  be,  in  the  asy- 
lum in  which  they  are  naturally  placed  at  birth.  It 
was  in  vain  that  Bonnet  endeavoured  to  preserve 
eggs  of  this  sort  in  his  chamber  till  spring,  in  conse- 
quc  nee,  he  imagines,  of  the  want  of  a  certain  degree 
of  moisture  which  they  would  have  had  out  of  doors 
We  have  been  more  successful,  through  the  precaution 
of  not  taking  the  eggs  from  their  native  tree  till  Feb- 
ruary, and  in  1830  we  had  a  brood  of  several  hundreds 
produced  of  the  oak  aphis  (Jlphis  Quercus).* 

The  failure  on  the  part  of  Bonnet  leads  us  to  re- 
mark, with  the  younger  Huber,  that  ants  are  more 
skilful  in  this  respect  than  naturalists,  and  anxiously 
nurse,  during  winter,  the  eggs  of  aphides,  which  they 
collect  with  great  care  in  the  autumn.  The  interest- 
ing narrative  of  the  discovery  of  this  we  shall  give  in 
Huber's  own  words. 

(  One  day  in  November,'  says  he,  '  anxious  to 
know  if  the  yellow  ants  (Formica  flava)  began  to 
bury  themselves  in  their  subterranean  chambers,  I  de- 
stroyed, with  care,  one  of  their  habitations,  story  by 

*  J.R. 
VOL.  vi.  10* 


114  INSECT    TRANSFORMATIONS. 

story.  I  had  not  advanced  far  in  this  attempt,  when 
I  discovered  an  apartment  containing  an  assemblage 
of  little  eggs,  which  -were  for  the  most  part  of  the 
colour  of  ebony.  Several  ants  surrounded  and  ap- 
peared to  take  great  care  of  them,  and  endeavoured, 
as  quickly  as  possible,  to  convey  them  from  my  sight. 
I  seized  upon  this  chamber,  its  inhabitants,  and  the 
treasure  it  contained. 

'  The  ants  did  not  abandon  these  eggs  to  make 
their  escape;  a  stronger  instinct  retained  them:  they 
hastened  to  conceal  them  under  the  small  d welling 
which  I  held  in  my  hand,  and  when  I  reached  home, 
I  drew  them  from  it,  to  observe  them  more  attentively. 
Viewed  with  a  microscope,  they  appeared  nearly  of 
the  form  of  ants'  eggs,  but  their  colour  was  entirely 
different;  the  greater  part  were  black;  others  were  of 
a  cloudy  yellow.  I  found  them  in  several  ant-hills, 
and  obtained  them  of  different  degrees  in  shade;  they 
were  not  all  black  and  yellow;  some  were  brown,  of  a 
slight  and  also  of  a  brilliant  red  and  white;  others 
were  of  a  colour  less  distinct,  as  straw  colour,  grayish, 
and  I  remarked  that  they  were  not  the  same  colour  at 
both  extremities. 

'  To  observe  them  more  closely,  I  placed  them  in 
the  corner  of  a  box  faced  with  glass;  they  were  col- 
lected in  a  heap  like  the  eggs  of  ants;  their  guardians 
seemed  to  value  then!  highly ;  after  having  visited  them, 
they  placed  one  part  in  the  earth,  but  I  witnessed  the 
attention  they  bestowed  upon  the  rest ;  they  approach- 
ed them,  slightly  separating  their  mandibles;  passed 
their  tongue  between  each,  extended  them,  then  walk- 
ed alternately  over  them,  depositing,  I  believe,  a  liquid 
substance  as  they  proceeded.  They  appeared  to  treat 
them  exactly  as  if  they  were  eggs  of  their  own 
species;  they  touched  them  with  their  antennae,  and 
frequently  carried  them  in  their  mouths;  they  did  not 
quit  these  eggs  a  single  instant;  they  took  them 


CARE    BY    ANTS    OF    EGGS   OF    APHIDES.          115 

up,  turned  them,  and  after  having  surveyed  them 
with  affectionate  regard,  conveyed  them  with  extreme 
tenderness  to  the  little  chamber  of  earth  I  had  placed 
at  their  disposal.  They  were  not,  however,  the  eggs 
of  ants;  we  know  that  these  are  extremely  white,  be- 
coming transparent  as  they  increase  in  age,  but  never 
acquire  a  colour  essentially  different.  I  was,  for  a 
long  time,  unacquainted  ^  jth  the  origin  of  those  of 
which  I  have  just  spoken,  and  by  chance  discovered 
they  contained  little  aphides;  but  it  wab  not  these  in- 
dividual eggs  I  saw  them  quit;  it  was  other  eggs 
which  were  a  little  larger,  found  in  the  nests  of  yellow 
ants,  and  of  a  particular  species.  On  opening  an  ant- 
hill, 1  discovered  several  chambers  containing  a  great 
number  of  brown  eggs,  of  which  the  ants  were  ex- 
tremely jealous,  carrying  them  with  the  utmost  expe- 
dition to  the  bottom  of  the  nest,  disputing  and  con- 
tending for  them  with  a  zeal  which  left  me  no  doubt 
of  the  strong  attachment  with  which  they  regard 
them. 

*  Desirous  of  conciliating  their  interests,  as  well  as 
my  own,  I  took  the  ants  and  their  treasure,  and  placed 
them  in  such  a  manner  that  I  might  easily  observe 
them.  These  eggs  were  never  abandoned.  The  ants 
took  the  same  care  of  them  as  the  former.  The  fol- 
lowing day  I  saw  one  of  these  eggs  open,  and  an 
aphis  fully  formed,  having  a  large  trunk,  quit  it.  I 
knew  it  to  be  a  puceron  of  the  oak:  the  others  were 
disclosed  a  few  days  after,  and  the  greater  number  in 
my  presence.  They  set  immediately  about  sucking 
the  juice  from  some  branches  of  the  tree  I  gave  them, 
and  the  ants  now  found,  within  their  reach,  a  recom- 
pense for  their  care  and  attention.  The.ant-hill  whence 
these  eggs  had  been  taken  was  situated  at  the  foot  of 
an  oak,  which  readily  accounts  for  their  existence  in 
that  place.  I  discovered  them  in  the  spring;  the  pu- 
cerons  which  quitted  them  were  very  large  for  insects 


116  INSECT    TRANSFORMATIONS. 

just  born,  but  they  had  not  yet  obtained  their  full 
size.'* 

It  is  not,  however,  the  aphides  themselves  who  select 
the  snug  winter  retreat  of  an  ant-hill,  or  who  know 
how  to  secure  the  careful  nursing  of  the  ants.  All 
this  is  the  sole  concern  of  the  latter,  to  secure  for  them- 
selves a  supply  of  the  honey-dew,  as  it  is  erroneously 
called,  secreted  by  the  aphides  in  spring.  The  ants, 
it  may  be  proper  to  remark,  take  similar  care  of  their 
own  eggs  (as  well  as  of  their  cocoons,  popularly  sup- 
posed to  be  their  eggs)  as  was  remarked  by  Sir  1C. 
King,  in  the  reign  of  Charles  II.  He  informs  us  that 
they  diligently  gather  together  in  a  heap  their  true 
eggs,  which  are  small  and  white  like  the  granules  of 
lump  sugar,  and  upon  these  e<*gs  they  lie  in  multi- 
tudes, i  I  suppose,'  says  Derham,  <  by  way  of  in- 
cubation. 'I  *  I  have  observed,'  adds  Sir  E.  King, 
1  in  summer,  that  in  the  morning  they  bring  up  those 
of  their  young  called  ant -eggs  (cocoons]  towards  the 
top  of  the  bank,  so  that  you  may,  from  ten  o'clock  till 
five  or  six  in  the  afternoon,  find  them  near  the  top,  — 
for  the  most  part  on  the  south  side.  But  towards 
seven  or  eight  at  night,  if  it  be  cool,  or  likely  to  rain, 
you  may  dig  a  foot  deep  before  you  can  find  them.'J 

An  interesting  family  of  two-winged  flies  (Hip- 
poboscidce,  LEACH)  resemble  the  aphides  in  some 
points  of  their  economy,  though  in  others  they  are 
singularly  peculiar.  R  aumur  discovered,  what  has 
been  recently  confirmed  by  Dufour  and  others,  that 
the  mothers  not  only  hatch  their  eggs  within  the  body, 
but  retain  them  there  till  they  are  changed  into  chry- 
salides. R  aumur  gives  a  lively  narrative  of  his 
discovery,  and  the  solicitude  of  his  servants  to  find  him 
female  flies  ready  to  deposit  what  he  at  first  took  for 

*  M.  P.  Huber  on  Ants,  p.  245. 

t  Derham,  Phys.  Theol.  ii,  207.  llth  ed. 

t  Phil.  Trans.  No.  xxiii. 


OVO-VIVIPAROUS    FLIES.  117 

eggs.  He  was  so  anxious  to  hatch  those  supposed 
eggs  that  he  carried  them  in  his  pocket  by  day  and 
took  them  to  bed  with  him  at  night,  (as  Bonnet  after- 
wards did  with  the  eggs  of  aphides,)  for  several  weeks 
successively;  but  instead  of  grubs,  as  he  had  expected, 
perfect  flies  were  evolved  exactly  similar  to  their  pa- 
rents. He  calls  them  spider  flies,  from  their  resem- 
blance to  spiders;  and  in  some  parts  of  France  the 
species  which  infests  horses  (Hippobosca  equina)  is 
called  the  Spaniard  or  Breton:  in  England  it  is  too 
well  known  under  the  name  of  the  forest  fly. 


Spider  flies  (Hippoboscidcp,  Leach.) 

We  have  the  more  willingly  introduced  this  sub- 
ject here,  that  another  fly  (Crattrina  Hirundinisy 
OJ.FERS),  of  the  same  family,  has  the  instinct  to  de- 
posit its  egg-like  cocoons  in  the  warm  feathery  nest  of 
swallows,  where  they  have  all  the  necessary  heat 
which  R  aumur,  in  his  experiments,  was  so  careful  to 
maintain.  In  return  for  the  warmth  which  the  young 
has  thus  received,  the  perfect  fly,  during  its  brief  ex- 
istence, lives  by  sucking  the  blood  of  the  swallows,  as 
the  one  first  mentioned  sucks  the  blood  of  horses, 
horned  cattle,  and;  it  is  also  said,  of  man. 


118  INSECT    TRANSFORMATIONS. 

The  effect  of  heat  upon  the  eggs  of  insects  has  been 
carried  much  farther  than  in  the  experiments  just 
alluded  to  of  R  aumur  and  Bonnet.*  Spallanzani 
was  desirous  of  ascertaining  what  degree  of  heat  the 
eggs  of  insects  and  other  animals,  as  well  as  the  seeds 
of  plants,  would  bear  when  compared  with  their  larvae; 
and  he  found  that  below  93°  Fahr.  silk-worms  did 
not  appear  affected,  but  at  95°,  and  still  more  at  97  °, 
they  became  restless,  while  at  99°  they  ceased  to  move, 
and  all  died  at  108°.  The  eggs  of  these,  on  the 
other  hand,  long  resisted  the  influence  of  heat.  At 
80°  they  were  the  most  productive;  at  99°  many  still 
appeared,  but  with  considerable  diminution,  and  as 
the  heat  was  increased  their  fertility  decreased,  till  at 
144°  not  one  was  fertile.  The  eggs  and  caterpillars 
of  the  elm  butterfly  (Vanessa  polychlorosl)  perfectly 
corresponded  with  those  of  the  silk-worm.  In  the  case 
of  the  eggs  of  the  blow-fly  (Musca  vomitoina)  a  great 
many  produced  maggots  at  124°;  but  at  135°  and 
138°  very  few,  and  all  were  sterile  at  140°.  The 
maggots  produced  from  these  eggs  became  restless  at 
88°,  and  endeavoured  to  escape,  and  as  this  heat  was 
increased  they  became  proportionably  more  agitated 
till  it  arose  to  108°,  when  they  all  perished.  Full- 
grown  maggots  of  the  same  kind  all  died  at  108°; 
but  when  changed  into  flies  they  died  when  the  heat 
was  so  low  as  99°;  though  their  pupae  were  produc- 
tive at  104°  and  106°,  but  not  at  lll°.t 

If  these  experiments  may,  as  we  believe  they  may, 
be  relied  on,  we  have  some  reason  to  doubt  that  '  the 
eggs  of  the  musca  vomiloria,  our  common  blow-fly, 
are  often,'  as  Dr  Good  affirms,  '  deposited  in  the 
heat  of  summer  upon  putrescent  meat,  and  broiled 
with  such  meat  over  a  gridiron  in  the  form  of  stakes,  in 
a  heat  not  merely  of  212°,  but  of  three  or  four  times 
°;  and  yet,  instead  of  being  hereby  destroyed,  we 

*  See  Insect  Architecture,  p.  24. 

t  Spallanzani,  Tracts  by  Dalyell,  vol.  i,  p.  85. 


EFFECTS   OF    HEAT    UPON    EGGS,  119 

sometimes  find  them  quickened  by  this  very  exposure 
into  their  larva  or  grub  state.'*  It  would  have  been 
well  if  some  more  accurate  authority  had  been  given  for 
so  miraculous  a  fact  than  this  general  statement:  the 
appearance  of  maggots  on  broiled  meat,  from  which  the 
inference  is  apparently  made,  seems  rather  to  indicate 
that  eggs,  or  more  probably  ovo-viviparcus  larvae,  had 
been  deposited  there,  not  before,  but  after  the  broiling. 

One  certain  result  of  all  such  experiments  is,  that 
eggs  are  more  capable  of  withstanding  heat  than  the 
animals  producing  them;  and  from  similar  experi- 
ments the  same  law  appears  to  hold  with  the  seeds 
of  plants,  which  also  withstand  more  heat  than  eggs. 
Water  increases  the  destructive  influence  of  heat. 
The  causes  upon  which  these  curious  facts  depend 
do  not  appear  to  be  well  understood  It  is  certain, 
however,  that  the  life  of  an  animal  in  the  egg  is  feeble, 
or  at  least  lethargic,  in  comparison  with  that  of  the 
animal  produced;  and  that  animals,  when  in  a  state  of 
very  feeble  animation,  resist  external  injuries  with 
more  impunity  than  when  very  vivacious.  We  once 
saw  a  very  delicate  young  girl,  emaciated  with  scro- 
fula, have  her  leg  amputated  without  even  heaving  a 
sigh;  while  a  robust  Irish  labourer,  who  underwent 
the  same  operation  immediately  after  her,  roared  like 
a  bull. 

Experiments  prove  that  the  fluids  of  eggs,  and  con- 
sequently of  their  germs,  are  more  abundant  than  in 
vegetable  seeds;  and  this  excess  of  fluid  may  tend  to 
destroy  the  germ  more  readily,  from  heat  expanding 
the  fluids,  and  thus  putting  them  in  motion:  for  then 
they  must  strike  violently  against  the  tender  parts  of 
the  germs,  arid  rupture  and  destroy  them.  Hence 
seeds  exposed  to  heat  are  killed  at  lower  degrees  in 
water,  than  if  dry,  in  the  same  way  as  ice  will  melt 
sooner  in  warm  water  than  in  air  of  equal  temperature. f 

*  Good's  Book  of  Nature,  vol.  i,  p.  221.     1st  edit. 
t  Spallanzani,  Tracts  by  Dalyell,  vol.  i,  p.  43. 


120  INSECT    TRANSFORMATIONS. 

In  the  practical  management  of  the  eggs  of  the  silk- 
worm, Count  Dandolo  directs  the  temperature  of  the 
stove-room  to  be  64°  when  they  are  first  put  in. 
c  The  third  day  the  temperature  should  be  raised  to 
66°;  the  fourth  day  to  68°;  the  fifth  day  to  71°;  the 
sixth  day  to  73°;  the  seventh  day  to  75°;  the  eighth 
day  to  77°;  the  ninth  day  to  80°;  the  tenth,  eleventh, 
and  twelfth  days  to  82°.  When  the  temperature  of 
the  stove-room  is  raised  to  75°,  it  is  advantageous  to 
have  two  dishes,  in  which  water  may  be  poured,  so  as 
to  offer  a  surface  of  nearly  four  inches  diameter.  In 
four  days  there  will  have  taken  place  an  evaporation 
of  nearly  twelve  ounces  of  water;  the  vapour,  which 
rises  very  slowly,  moderates  the  dryness  which  might 
occur  in  the  stove-house,  particularly  during  a  north- 
erly wind:  very  dry  air  is  not  favourable  to  the  devel- 
opment of  the  silk-worm.'*  Damp  or  stagnant  air, 
or  sudden  changes  of  temperature,  either  high  or  low, 
are  exceedingly  injurious  to  the  hatching  of  eggs. 

From  some  very  curious  experiments  of  Michelotti, 
it  appears  that  exposure  to  light  is  by  no  means  favour- 
able to  the  hatching  of  eggs  This  ingenious  natural- 
ist i  sclosed  a  number  of  eggs  in  glass  vessels,  admit- 
ting the  light  to  one  series  and  excluding  it  from 
another,  similar  in  every  other  particular.  The  result 
was,  that  few  or  none  of  the  eggs  exposed  to  light 
were  hatched,  while  those  in  the  dark  were  almost  all 
fertile.  He  arrived  at  the  same  results  in  his  experi- 
ments upon  vegetable  seeds. "f  Kirby  and  Spence 
justly  remark,  that  these  curious  facts  may  account 
for  so  many  insects  fastening  their  eggs  to  the  under 
sides  of  leaves,  and  may  be  the  final  cause  of  the 
opaque  horny  texture  of  those  exposed  in  full  day.J 

Among  the  singular  circumstances  in  which  insects 
differ  from  the  larger  animals,  we  may  reckon  that 

*  Count  Dandolo,  on  Silk- Worms,  Eng.  trans.,  p.  55. 

t  Philosophical  Mag.,  vol.  ix,  p.  244.    |  Introduc.  iii,  p.  77. 


INCREASE    IN    SIZE    OF    EGGS. 


121 


of  the  eggs  of  some  increasing  in  size  during  the  pro- 
cess of  hatching.  The  fact  appears  to  have  first  been 
noticed  by  the  celebrated  Vallisnieri  in  his  observa- 
tions on  saw-flies  (Tenihredinidcz,  LEACH).*  Other 
instances  were  subsequently  discovered  by  R  aumur, 
De  Geer,  Derham,  R'  sel,  and  the  younger  Huber. 
'  It  ought  not,'  says  R  aumur,  speaking  of  gall  flies 
( Cympidce,  WEST  WOOD),  '  to  be  passed  in  silence, 
that  the  egg  which  I  found  in  the  gall  appeared  to 
me  considerably  larger  than  the  eggs  of  the  same  spe- 
cies when  they  proceed  from  the  body  of  the  fly,  or 
even  when  they  are  taken  from  the  mother  fly  near  the 
time  of  their  being  laid.  The  whole  of  those  I  took 
front  the  mother  flies  which  I  killed  were  remarkably 


Generation  of  a  water-mite  (Hydra-hna  alstergens). 
a  a,  the  water  scojpion,  in  whose  body  the  mite  fixes  her  eggs. 
6  b,  a  magnified  view  of  one  of  its  claws,  c,  a  tooth-like  process  for 
restraining  the  motion  of  the  joint.  <Z,  the  water-mite,  e,  a  greatly 
magnified  view  of  one  of  its  eggs,  y,  the  hook  by  which  it  is  inserted 
into  the  body  of  the  scorpion. 

*  See  Insect  Architecture,  pp.  157-8. 
VOL.  VI.  11 


122  INSECT    TRANSFORMATIONS. 

small;    and  I   thence    inferred   that   the    egg    would 
have,  and  indeed  had,  increased  in  the  gall.'* 

R  'sel  made  a  similar  observation  on  the  red  eggs 
of  a  water-rnite  (Hydrackna  abstergens) ;  and  he  was 
induced  to  suppose  (justly,  as  we  think)  that,  as  they 
are  deposited  upon  the  bodies  of  water-scorpions 
(Nepidw,  LEACH),  they  derive  their  means  of  in- 
crease from  them.J  De  Geer  remarked  that  the 
water-scorpions,  when  much  infested  with  them,  be- 
came gradually  weakened  as  the  eggs  increased  in 
size.J 

Huber  the  younger,  in  the  course  of  his  experi 
ments,  discovered  that  the  eggs  of  ants,  from  being 
small  and  opaque,  became  comparatively  large*  and 
transparent.  '  To  be  convinced  of  the  truth  of  this,' 
he  says,  '  I  viewed  those  eggs  with  the  microscope. 
I  also  measured  them,  and  having  separated  them 
from  each  other,  found  the  longest  to  be  those  only 
in  which  the  grubs  were  hatched  in  my  presence. 
If  I  removed  them  from  the  workers,  before  they 
attained  their  full  length  and  transparency,  they  dried 
up,  and  the  grubs  never  quitted  them.'  Huber  is 
inclined  to  attribute  this  remarkable  increase  and 
transparency  to  the  humidity  imparted  to  them  by  the 
working  ants  who  so  assiduously  pass  them  through 
their  mouths.  c  For,'  he  adds,  '  if  they  be  not  sur- 
rounded with  a  liquid,  or  preserved  from  the  influence 
of  the  external  air,  their  pellicle,  moistened  every 
instant  by  the  workers,  may  preserve  a  certain  degree 
of  suppleness  and  expansibility,  according  to  the  de- 
velopment of  the  included  grub.'^ 

The  most  minute  observations,  however,  of  this 
kind,  which  have  hitherto  been  published^  were  made 

*  R'aumur,  Mem.  vol.  iii,  p.  479. 

t  R  sel,  Insecten,  vol.  iii,  p.  152. 

4"  De  Geer,  Mem.  des  Insectes,  vol.  vii,  p.  145. 

§  M.  P.  Huber  on  Ants,  p.  72. 


DEVELOPMENT    OF    EGGS.  123 

by  Heroldt  on  the  eggs  of  the  garden  spider  (Epeira 
diadcma],  to  which  we  formerly  alluded.     He  divides 
the  process  of  hatching  into  twelve  periods,  according 
to  the  progress  of  development.     This  progress  is  not 
measured  by  time,  as  has  been  done  in   experiment- 
ing on  the  eggs  of  birds.     The  germ,  or  cicatricula, 
which  is  composed  of  minute  granules,  when  placed 
in  a  due  temperature,  begins  to  expand  towaids  the 
extremity  of  the  egg,  till  it  takes  the  form  of  a  comet, 
whose  nucleus  is  the  centre  of  the  germ,  and  whose 
tail*  consists  of  transparent  globules.     On   continuing 
to   expand,  or  rather  to  disperse   its  granules,   they 
appear   to   be    decomposed  into  imperceptible    mole- 
cules, producing  a  sort  of  translucent  cloud,  through 
which  the  globules  of  the  yolk  may  be  distinguished. 
The   place  which  the  germ  previously  occupied  ap- 
pears   as    a   single  transparent   point.      The    cloudy 
matter    next    accumulates   round   the    centre   of  the 
germ,  assumes  a  pearly  aspect,  and  becomes  solid  and 
opaque.     This  is  the  rudiment  of  the  embryo  spider, 
the  outline  of  whose  head  and  body  becomes  appa- 
rent, occupying  a  little  more  than  a  fourth  of  the  egg. 
At  first  this  embryo  appears  homcgeneous,  but  by  and 
by  four  little  archlets  are  seen,  which  are  the  rudi- 
ments of  the  legs,  and  at  the  same  time  the  outlines 
of  the  mandibles  are  formed.     The  whole  seems  to 
derive  nourishment  from  the  yolk,  in  which  it  is  rooted 
as  a  parasite  plant  upon  a  tree.     When  the  embryo 
spider  is  near  its  exclusion,  it  completely  fills  the  inte- 
rior of  the  egg,  the  shell  of  which  moulds  itself  close- 
ly around  the  body,  and  it  looks  like  the  nymph  of  a 
beetle.*    When  sufficiently  developed,  it  makes  a  rent 
in  the  shell,  as  was  first  observed  by  De  Geer,  oppo- 
site the  breast,  through  which  it  pushes  its  head,  and 
successively  disengages  its  body;    but  the  shell  still 
envelopes  the  legs  and  feet,  and  it  is  not  without  a 

*  Heroldt,  Exercit.  de  Gener.  Aranearum  in  Ovo. 


124 


INSECT    TRANSFORMATIONS. 


great  deal  of  trouble,  by  alternately  stretcbing  out  and 
contracting  them,  that  it  succeeds  in  rending  this,  and 
sets  itself  at  liberty.*  Even  then  the  young  spider  can 
neither  spin  a  web  nor  catch  prey;  for  it  is  still  en- 
veloped in  an  extremely  delicate  membrane,  which  it 
does  not  moult  unless  the  weather  is  favourable  and 
fine. 


Hatching  of  the  egg  of  the  garden  spider  (Epcira  diadema). '  a,  natural 
size.  6,  egg  magnified,  the  ckatricula  (a  white  spot)  in  the  front.  C,  the 
germ  enlarged ;  u,  the  head,  and  6,  the  body  of  the  embryo,  d,  the  em- 
bryo spider  ready  to  cast  off  its  first  skin. 

The  latter  circumstance  will  enable  us  to  explain 
some  experiments  made  by  Redi,  who  kept  spiders 
newly  hatched  for  many  months  without  food.j  In 
the  experiments  made  by  us  upon  the  eggs  of  the  wolf 
spider  (Lycosa  saccata),  we  more  than  once  kept  the 
young  in  boxes,  where  they  were  forgotten  and  without 
food;  and  we  uniformly  found  that  they  remained  lively 
and  well  so  long  as  they  did  not  cast  their  embryo 
skin;  but  when  they  did  moult,  they  could  not  long 
survive  the  want  of  sustenance.^ 

In  the  eggs  of  moths,  the  embryo,  previous  to  ex- 
clusion, may  be  seen  through  the  shell,  snugly  coiled 

*  De  Geer,  Mem.  vii,  p.  196. 

t  Diet.  Classique  d'Hist.  Nat.  xii,  141. 

}  Redi,  Esperienze,  99.  §  J.  R. 


CONSTRUCTION    OF    EGGS. 


125 


up  in   a  ring,  as  is  distinctly  shown  in  many  of  the 
beautiful  and  accurate  figures  of  Sepp.* 


«,  egg  of  the  privet  hawk-moth  fSntn'nx  Li^-ustn)  magnified, 
showing   the  inclosed  embryo,    fc,  the  caterpillar,  when  grown. 

In  the  case  of  the  eggs  of  birds,  the  chick,  when 
fully  developed,  breaks  the  shell  with  its  bill,  the 
point  of  which  is  then  furnished  with  a  hard  scale. 
This  is  evidently  contrived  by  providential  wisdom  for 
this  very  purpose,  for  it  drops  off  in  a  few  days  after 
the  chick  is  excluded.  It  is  probable  that  the  larvae 
of  many  insects  which  are  furnished  with  strong  man- 
dibles gnaw  their  way  through  the  egg-shell;  but  we 
know  that  there  are  others  which,  like  the  spider, 
rupture  their  envelope,  since  the  edges  appear  ragged 
and  irregular.  Others,  again,  seem  to  have  an  open- 
ing provided  for  them,  in  a  door,  which  only  requires 
them  to  push  it  open.  This  is  the  case  with  the  louse 
(Pediculus  hwnanus},  and  with  the  bird-louse  (Nir- 
mws),  found  on  the  neck  feathers  of  the  golden  phea- 
sant. A  still  more  ingenious  contrivance  was  discov- 
ered by  the  Rev.  R.  Sheppard^  in  the  egg  of  a  f  eld 
bug  (Pentaloma,  LATR.),  which  is  not  only  furnish- 


voi..   vi. 


*  Per  Wonderen  Gods,  passim. 
11* 


126  INSECT    TRANSFORMATIONS. 


Doors  in  eggs  for  the  escape,  of  the  larvae. 

a,  egg  of  the  louse  (Ft  icu/us  humamts).  6,  egg  of  the  pentato- 
ma.  c,  shell  of  a  moth's  egg  found  upon  the  dew-berry,  all  mag- 
nified. 

ed  with  a  convex  lid,  but  with  a  lever  of  a  horny  tex- 
ture, and  in  the  form  of  a  cross-bow,  for  opening  it, 
the  handle  being  fixed  to  the  lower  part  of  the  egg  by 
a  membrane,  and  the  bow  part  to  the  lid.*  On  the 
leaf  of  a  dew-berry  (Rnbus  ccesius)  we  found  a  beau- 
tifully ribbed  egg  of  some  moth,  which,  having  been 
brought  into  our  study  in  January,  1830,  was  hatch- 
ed by  the  warmth,  and  exhibited  an  opening  similar 
to  the  elastic  cocoon  of  the  emperor-moth;  each  of 
the  ribs  having  expanded  to  allow  of  the  escape  of  the 
caterpillar. 

The  period  at  which  the  eggs  of  insects  are  hatch- 
ed atter  deposition  depends  mainly  upon  temperature; 
for  by  keeping  them  in  an  ice-house  in  summer,  the 
hatching  may  be  retarded, |  as  it  may  be  hastened 
(witness  the  instance  in  the  preceding  paragraph)  by 
heat  in  winter;  but  there  are  many  other  circumstan- 
ces unknown  to  us  which  often  hasten  or  retard  the 
process.  The  eggs  of  the  blow-fly  (Musca  vomito- 
ria)  are  said  to  hatch  within  two  hours,  J  while  those 
of  several  moths,  and  numerous  other  insects,  remain 
unhatched  for  six  or  nine  months;  perhaps,  in  some 
cases,  even  for  one  or  more  years.  It  is  worthy  of 

*  Kirby  an4  Spence,  iii,  104.  t  Reaumur,  Mem. 

£  Nouv.  Diet.  d'Hist.  Nat.  xii,  564. 


PERIODS    OF    HATCHING.  127 

remark,  however,  that  the  periods  of  hatching  corre- 
spond in  a  striking  manner  with  the  leafing  of  trees, 
and  the  appearance  of  other  materials  fitted  for  the 
food  of  the  young.  We  observed  a  good  exampla  of 
this  in  the  spring  of  1829.  A  lackey  moth  had  de- 
posited during  autumn  a  spiral  ring  of  her  eggs  on  the 
branch  of  a  sweet-briar  planted  in  a  garden-pot  out 
of  doors.  We  removed  this  into  our  study  during  the 
winter.  Here  the  warmth  caused  the  tree  to  bud, 
and  at  the  same  time  hatched  the  lackeys  about  a 
month  sooner  than  those  out  of  doors.  Owing  to  the 
same  cause,  several  colonies  of  the  caterpillars  of  the 
brown-tail  moth  revived  from  their  torpidity,  and  came 
forth  from  their  winter  nests  before  the.  hawthorns 
were  in  leaf,  a  circumstance  which  would  not  have 
happened  to  them  out  of  doors. *  Kirby  and  Spence 
give  an  instance  precisely  similar,  of  the  eggs  of  an 
aphis  found  on  the  birch,  and  hatched  in-doors  a  full 
month  before  those  in  the  open  air.f 

It  is  a  remarkable  circumstance,  long  observed  by 
collectors,  that  the  male  broods  of  insects  appear 
earlier  than  the  female  broods;  and  it  would  appear 
from  the  following  fact,  that  there  is  a  similar  retarda- 
tion in  the  hatching  of  female  eggs.  '  Upon  the  leaf 
of  a  poplar  tree  were  found  three  eggs  of  the  puss 
moth  (Centra  mnula),two  of  which  were  hatched 
about  two  weeks  before  the  other.  The  first  were 
males,  the  last  a  female.  As  they  were  on  the  same 
leaf,  and  presumed,  therefore,  to  have  been  laid  by 
the  same  parent,  at  the  same  time,  the  difference  of 
hatching  could  not  have  arisen  from  difference  of  wea- 
ther, exposure,  &c.'J  In  the  case  of  the  lackeys  on 
the  sweet-briar  above-mentioned,  some  were  hatch- 
ed several  days  before  others,  but  whether  these  were 
of  different  sexes  we  did  not  ascertain. 

*  J.  R.  t  Kirby  and  Spence,  Intr.  ii,  434. 

t  J.  Rennie,  in  Mag.  of  Nat.  Hist.,  vol.  i,  p.  373. 


SECTION  II.  — LARVJE.* 


CHAPTER  VI. 

Structure  of  Caterpillars,  Grubs,  and  Maggots. 

IT  is  reported  by  Boerhaave,  in  his  life  of  Swam- 
merdarn,  that  when  the  Grand  Duke  of  Tuscany  was 
visiting  the  curiosities  of  Holland,  in  1668,  he  found 
nothing  more  worthy  of  his  admiration  than  the  na- 
turalist's account  of  the  structure  of  caterpillars,  —  for 
Swarnmerdam,  by  the  skilful  management  of  instru- 
ments of  wonderful  delicacy  and  fineness,  showed 
the  prince  in  'what  manner  the  future  butterfly  lies 
neatly  folded  up  in  the  caterpillar,  like  a  flower  in 
the  unexpanded  bud.  He  was,  indeed,  so  struck 
with  this  and  other  wonders  of  the  insect  world,  dis- 
closed to  him  by  the  great  naturalist,  that  he  made 
him  a  princely  offer  to  induce  him  to  reside  at  his 
court;  but  Swarnmerdam,  from  feelings  pf  indepen- 
dence, modestly  declined  to  accept  it,  preferring  to 
continue  his  delightful  studies  at  home.  The  facts 
which  thus  struck  the  Duke  with  admiration,  we  shall 
now  endeavour,  with  the  aid  of  Swammerdam,  to 
trace.  But,  before  we  proceed,  it  may  not  be  out  of 
place  to  advert  to  some  very  novel  views  which  have 

*  It  may  be  proper  to  repeat  here,  that  an  insect,  when 
hatched  from  the,  egg,  is  called  by  naturalists  It  rva  ;  and  in 
popular  language,  a  caterpillar  or  grub,  if  furnished  with  feet, 
and  a  maggoty  worm,  or  gentle,  if  without  feet. 


ANIMAL  AND  VEGETABLE  TRANSMUTATIONS.  129 

been  recently  started  by  continental  naturalists,  who 
maintain  that  vegetables  are  actually  converted  into 
animals,  and  these  again  into  vegetables. 

It  must  be  obvious,  we  think,  from  the  details  we 
have  already  given,  that  the  doctrine  of  transmuta- 
tion, so  far  as  regards  insects,  is  equally  absurd  and 
impossible  with  the  pretended  alchemical  transmuta- 
tion of  lead  and  other  inferior  metals  into  gold  and 
silver;  which  doctrine  was,  indeed,  supported  upon 
the  supposed  fact  of  insects  being  thus  transmuted.* 
But  visionary  as  either  of  these  may  appear,  they  have 
both  been  supported  by  men  of  talent  and  distinguish- 
ed reputation.  It  does  not,  perhaps,  at  first  sight 
seem  more  impossible,  that  water  should  be  transmu- 
ted into  diamonds,  or  brass  into  gold,  than  that  an 
egg  should  disclose  a  chick  or  a  caterpillar,  or  that  a 
caterpillar  should  change  into  a  butterfly  or  a  beetle; 
but  by  adhering  rigidly  to  facts,  and  rejecting  as  rigid- 
ly all  fancies  and  analogies,  how  plausible  soever  they 
may  appear,  we  are  certain  that  the  latter  changes  are 
of  common  occurrence,  whereas  the  former  are  con- 
trary to  all  experience,  and  to  the  best  experiments. 
We  say  the  best;  because  observations,  if  not  experi- 
ments, have  been  made  for  the  express  purpose  of 
proving  such  improbable  transmutations. 

'  I  have  shown  to  a  great  number  of  persons,'  says 
Professor  Agardh,  c  the  changeable  crow-silk  (Con- 
ferva mutabiliS)  ROTH;  Draparnaldia  m.  BORY  ST 
V.)  in  its  state  of  a  plant,  the  3d  of  August,  change 
by  the  5th  into  molecules  endowed  with  locomobility, 
reunite  by  the  6th  into  simple  articulations,  and  recon- 
stituted by  the  10th  into  the  primitive  form  of  the 
plant.'!  Previous  to  this  (in  1814)  Professor  Nees 
von  Esenbeck,  of  Bonn,  published  similar  observa- 

*  Sir  Theodore  May  erne,  Epist.  Dedicat  ad  Theatrum  In- 
sect. Mouffetii. 

t  Agardh,  Diss.  de  Metamorph.  Algarum,  1820. 


130  INSECT       TRANSFORMATIONS. 

tions,  in  which  he  remarks,  that  c  as  the  phenomena  in 
question  appear  to  contradict  certain  principles  admit- 
ted into  the  reigning  systems,  we  often  prefer  rather 
to  deny  the  conclusions  of  candid  and  experienced 
observers,  than  to  receive  what  has  hitherto  been  re- 

farded  as  untenable  by  generally  admitted  authority 
n  this  situation  are  placed  all  observations  upon  the 
transition  or  metamorphosis  of  vegetable  life  (charac- 
terised by  immobility)  into  animal  lite  (characterised 
by  mobility);  —  the  moment  when  a  being,  arrived  at 
the  period  of  its  existence,  continues  itself,  as  it  were, 
by  a  new  creation,  and  the  animated  embryo  develops 
itself  into  a  motionless  vegetable.'*  Agardh,  in  his 
account  of  another  allied  family  (Ocillatoriaz),  has 
even  given  figures,  first  of  the  plant,  and  then  of  the 
animalcules  into  which  its  filaments  are  converted,")* 
which  induced  Bory  St  Vincent  to  remark  sarcasti- 
cally, that  4  all  nature  appears,  to  the  Professor  of 
Lund,  to  be  nothing  but  confervce  travestied. 'J 

Passing  over  what  has  been  published  on  this 
strange  doctrine  by  Vaucher,  Girod-Chantrans,  Tre- 
viranus,  Cams,  and  others,  we  shall  only  stop  to 
mention  the  more  recent  observations  of  Francis 
Unger.  The  plant  he  selected  was  the  Conferva 
dilatata  ft  of  Roth.  <  Within  the  space  of  one  hour,' 
says  he,  '  I  succeeded  in  tracing,  not  only  the  dimi- 
nution of  vitality  and  death  of  the  animalcules,  but 
also  the  subsequent  development  of  the  dead  animals 
into  germinating  plants,  in  such  a  manner  as  to 
establish  the  truth  of  the  fact.'  He  adds  with  great 
simplicity,  '  I  could  scarcely  believe  ray  own  eyes.'§ 
Like  Agardh,  he  has  given  figures  of  these  miracu 

*  Quoted  in  '  Annales  des  Sciences  Naturelles'  for  1828, 

t  Agardh,  Icones  Alg.  ined-  i,  10. 

J  Diet.  Classique  d'Hist.  Nat.,  x,  469. 

§  Annales  des  Sciences  Nat.,  1828, 


ANIMAL    AND    VEGETABLE    TRANSMUTATIONS.     131 

lous  changes,  which  our  readers  may  be  curious  to 
see. 


Supposed  animal  and  vegetable  metamoiphoses. 


Since  the  only  proof  of  these  plants  being  trans- 
muted   (as    is    alleged)    into  animals,  appears  to  be 
their    acquiring     motion,*     and,     as     linger    says, 
'  swimming    freely    about;'  we   think    we    should  be 
equally  entitled    to   infer   that    camphor  is  animated 
because    it    moves    spontaneously  when  thrown  into 
water.     This    property    in   camphor  has  not  hitherto 
been  satisfactorily   explained;  and   it   would  undoubt- 
edly be  better  to   leave   the  phenomena  described   by 
our  advocates  for  transmutation  likewise   unexplained, 
than  to  leap  at    once  to  their  startling  conclusions.. 
'  We    might    as    well,'    says    Bory      St     Vincent, 
4  astonish    the    world    with    the    discovery  of   a  fig- 
tree  transmuted   into   a   mulberry  tree,   because    the 
Broussonetia,  when  young,  has  the  leaves  of  the   one, 
and  when  old  of  the  other;  and  by    such  a  system  of 
observing  we  shall  end  in   looking   upon  the  oak  and 
the  mistletoe  as  the  same  plant:  the  wand  of  Circe 
could    not    produce    more    astounding   consequences 

*  Nees  von  Esenbeck. 


132  INSECT    TRANSFORMATIONS. 

than  the  microscope  does  in  the  hands  of  such   ob- 
servers.'* 

It  is  apparently  a  branch  of  the  same  untenable 
theory,  which  maintains  that  the  fluid  termed  by 
Heroldt  the  blood  of  caterpillars  is  the  only  original 
portion  of  them,  which,  being  endowed  with  a  forma- 
tive power,t  produces  an  envelope  for  itself  of  mucous 
net-work  (rete  mucosum),  and  this  again,  by  means  of 
a  similar  power,  is  successively  transmuted  into  the 
caterpillar,  the  pupa,  and  the  perfect  insect ;J  in  some 
similar  way,  we  suppose,  to  the  formative  power  dis- 
played by  water,  when,  during  frost,  it  shoots  into 
crystals  of  ice.  But  the  framers  of  such  theories  seem 
to  forget  that  living  blood  is  a  very  different  thing 
from  inanimate  water,  and  the  growth  and  nutrition 
of  animals  from  the  chemical  formation  of  crystals. 
Kirby  and  Spence  very  justly  remark,  that  Heroldt's 
formative  power  is  only  an  apology  for  ignorance,  and 
that  his  denying  the  existence. of  what  he  cannot  trace, 
is  no  proof  of  his  doctrine,  but  of  his  mistake  in  sup- 
posing the  first  appearance  of  the  organs  of  the  but- 
terfly in  his  microscope  to  be  literally  their  first 
existence.  To  suppose  the  blood,  we  may  also  re- 
mark, endowed  with  the  power  of  creating  insects,  gets 
rid  of  no  difficulty  and  explains  no  phenomenon,  while 
it  is  altogether  a  gratuitous  assumption,  unproved 
and  improbable.  c  Admirable  discovery,'  exclaims 
Virey;  '  as  if  you  should  affirm  that  a  stone  falls 
because  it  falls  !'§  We  think  it  is  St  Pierre  who 
remarks,  that  Nature  seldom  permits  philosophers  to 
peep  to  the  bottom  of  her  basket ;  and  we  have  already 

*  Diet.  Class.  d'Hist.  Nat.  x,  468. 

t  The  German  term  is  c  Bildende  Kraft,'  i.  e.    Vis  forma- 
trix,  or  JVisus  formativus. 

t  Heroldt,  quoted  by  Kirby  and  Spence,  hi,  83. 
§  Quoted  by  Kirby  and  Spence. 


EMBRYO    BUTTERFLIES.  133 

recorded  many  instances,  besides  the  one  under  con- 
sideration, of  their  strange  mistakes  in  guessing  at 
what  they  cannot  fathom.  We  prefer  following  Swam- 
merdam,  Reaumur,  and  Bonnet,  in  recording  what 
can  be  actually  seen  on  examining  the  structure  of 
caterpillars. 

In  a  chapter  of  Swammerdam's  Book  of  Nature, 
quaintly  headed  c  An  animal  in  an  animal,  or  the 
butterfly  hidden  in  the  caterpillar,'  we  find  the  fol- 
lowing details  respecting  the  caterpillar  of  the  large 
cabbage  butterfly  (Pontia  brassicce).  The  egg  of 
this  insect  is  of  a  yellow  colour,  flask  shaped,  and 
marked  with  fifteen  ribs,  converging  towards  the 
smaller  end,  and  extending  a  little  beyond  it.  The 


Egg  of  the  large  cabbage  butterfly  (Pontia  brassica),  magnified. 

caterpillar,  but  too  well  known  from  its  ravages,  has 
sixteen  feet,  a  yellow  line  along  the  back,  and  another 
on  each  side,  the  rest  of  the  body  being  bluish  gray, 
spotted  with  black;  and  the  whole  surface  sprinkled 
with  thin,  short,  whitish  hairs.* 

1  In   order,'   continues   Swammerdam,  '  to  discover 
plainly  that  a  butterfly  is  inclosed  and  hidden  in  the 

*  Ray,  Cat,  Cantab.,  quoted  by  Swammerdam.    See  fig.  a, 
page  62. 

VOL.   VT.  12 


134  INSECT    TRANSFORMATIONS. 

skin  of  this  caterpillar,  the  following  operation  must 
be  used.  One  must  kill  a  full-grown  caterpillar,  tie  a 
thread  to  its  body,  and  dip  it  for  a  minute  or  two  into 
boiling  water.  The  outer  skin  will,  after  this,  easily 
separate,  because  the  fluids,  between  the  two  skins, 
are  by  this  means  rarefied  and  dilated,  and  therefore 
they  break  and  detach  both  the  vessels  and  the  fibres 
wherewith  they  were  united  together.  By  this  means 
the  outer  skin  of  the  caterpillar,  being  separated,  may 
be  easily  drawn  off  from  the  butterfly  which  is  contain- 
ed and  folded  up  in  it.  This  done,  it  is  clearly  and 
distinctly  seen,  that,  within  this  skin  of  the  caterpillar, 
a  perfect  and  real  butterfly  was  hidden,  and  therefore 
the  skin  of  the  caterpillar  must  be  considered  only  as 
an  outer  garment,  containing  in  it  parts  belonging  to 
the  nature  of  a  butterfly,  which  have  grown  under  its 
defence  by  slow  degrees,  in  like  manner  as  other  sen- 
sitive bodies  increase  by  accretion. 

f  But  as  these  limbs  of  the  butterfly  which  lie  under 
the  skin  of  the  caterpillar  cannot,  without  great  diffi- 
culty, be  discovered  in  the  full-grown  caterpillar,  unless 
by  a  person  accustomed  to  such  experiments,  —  because 
they  are  then  very  soft,  tender,  and  small,  and  are 
moreover  complicated  or  folded  together,  and  inclosed 
in  some  membranaceous  coverings,  —  it  is,  therefore, 
necessary  to  defer  the  operation  just  now  proposed, 
until  the  several  parts  of  the  butterfly  become  some- 
what more  conspicuous  than  at  first,  and  are  more 
increased  and  swelled  under  the  skin  by  the  force  of 
the  intruded  blood  and  aqueous  humour.  This  is 
known  to  be  the  case  when  the  caterpillar  ceases  to  eat, 
and  its  skin  on  each  side  of  the  thorax,  near  under  the 
head,  is  then  observed  to  be  more  and  more  elevated 
by  the  increasing  and  swelling  limbs,  and  shows  the 
appearance  of  two  pairs  of  prominent  tubercles.'* 

*  Swammerdam,  Book  of  Nature,  ii,  26. 


EMBRYO    BUTTERFLIES. 


135 


Embryo  butterflies  (Pontia  Brasaicat),  as  they  appear  in  the 
bodies  of  caterpillars.  The  wings,  antennae,  and  trunks  in  the 
figures  are  spread  out  to  show  them. 

By  similar  dissections,  Malpighi  both  actually  dis- 
covered the  moth  in  the  body  of  a  silk  worm,  and  also 
the  eggs  of  it;*  and  R'aumur  made  a  similar  disco- 
very in  the  caterpillar  of  the  gypsey  moth  (Uypogymna 
dispar).-\ 


Female  of  the  perlect  cabbage  butterfly  (Pontia  brassiccc.) 

In  order  to  harden  the  parts  of  the  incipient  butterfly 
that  are  soft,  Swammerdam  immersed  the  caterpillar 
in  a  phial  filled  with  equal  parts  of  vinegar  and  spirit 
of  wine  for  sixteen  hours,  when  he  found  it  would 

*  Malpighi  de  Bombyce,  29.         t  Reaumur,  Mem.  i,  359. 


136  INSECT    TRANSFORMATIONS. 

better  bear  handling.  It  may  be  necessary  to  remark, 
that  though  all  the  parts  of  the  butterfly  are  in  this 
manner  discoverable  in  the  caterpillar,  they  are  only 
in  the  bud,  if  we  may  use  the  expression,  and  appear  to 
be  out  of  proportion  from  being  so  closely  folded  up  and 
unexpanded.  The  whole,  indeed,  bears  so  much  ana- 
logy to  the  embryo  of  a  plant  in  the  seed,  or  the  rudi- 


«,  greatly  magnified  view  of  a  section  of  the  bud  of  the  labur- 
num. It  exhibits  the  nascent  flowers,  arranged  in  regular  order, 
previously  to  their  bursting  into  perfect  existence,  b.  section  of 
a  bean  seed,  c,  seed-leaves,  root,  and  the  first  true  leaf  of  the 
beech. 


CONSTRUCTION    OF    THE    CATERPILLAR.         137 

ments  of  a  leaf,  or  of  a  flower  in  the  bud,  that  Swam- 
merdam  has  given  figures  of  the  parallel  developments 
of  larvae  and  of  a  carnation.  His  selection  of  this  flower 
was  not  perhaps  the  most  happy ;  but  our  readers  may 
readily  obtain  examples  by  carefully  dividing  the  un- 
expanded  buds  of  the  rose,  the  lilac,  the  horse-chestnut, 
the  American  walnut,  or  beans,  and  other  large  seeds 
after  they  have  been  planted  in  moist  earth,  but  not 
left  long  enough  to  shoot  into  a  plant.  The  preceding 
figures  will  illustrate  this  better  than  description.  Dr 
Grew  proved  in  this  manner  that  flowers  which  blow 
in  spring  are  formed  in  the  preceding  year;*  and  Du 
Hamel,  on  dissecting,  in  January,  the  bud  of  a  pear- 
tree,  found  under  an  envelope  of  about  thirty  leaf  scales 
eight  or  ten  embryo  flowers  resembling  rose-buds  be- 
studded  with  hairs. f 

The  butterfly  and  the  flower-bud,  however,  differ  re- 
markably in  the  manner  in  which  they  are  nourished, — 
the  latter  receiving  sap  from  the  enveloping  leaf  scales, 
the  former  taking  food  into  the  stomach  through  the 
mouth  of  the  caterpillar.  The  stomach,  indeed,  of  the 
inclosed  butterfly  is  so  capacious,  that  it  fills  the  greater 
portion  of  its  body ;  and  requires  the  caterpillar  to  occu- 
py almost  its  whole  time  in  eating  in  order  to  satisfy  its 
cravings.  When  the  food  is  digested  in  the  stomach 
of  the  insect,  it  passes,  as  in  the  larger  animals,  into 
the  small  intestines  ;J  but  it  is  not,  as  in  them,  col- 
lected by  innumerable  little  vessels  which  afterwards 
run  into  one,  (as  brooks  unite  to  form  a  river,)  and  go 
to  the  lungs  to  be  exposed  to  the  air,  supplied  by 
breathing,  in  order  to  be  there  oxygenated  and  formed 
into  red  blood.  Insects,  on  the  contrary,  do  not 

*  Grew.  Phys.  Veg.,  ii,  60. 
t  Du  Hamel,  Physique  des  Arbres,  iii,  1. 
$  See  *  Insect  Architecture,'  p.   309,  D,  D.;  and  this  vol. 
p.  198. 

VOL.  VI.  12* 


138  INSECT    TRANSFORMATIONS. 

breathe  by  the  mouth,  and  are  not  furnished  with 
lungs;  for  though  good  air  is  no  less  essential  to  their 
nutrition  and  existence,  it  is  brought  to  act  on  the  di- 
gested food  in  a  different  manner.  In  caterpillars,  and 
in  most  perfect  insects,  the  air  is  respired  by  breath- 
ing-tubes—  usually  eighteen  in  number  —  placed  along 
the  sides,*  the  mouths  of  which  may  be  seen  moving, 
as  the  air  passes  in  and  out,  from  ten  to  thirty  times 
in  a  minute.  When  these  are  covered  with  oil,  or  any 
other  matter  preventing  the  entrance  of  the  air,  the 
insect,  being  unable  to  breathe,  is  suffocated  and  dies, 
as  was  observed  two  thousand  years  ago  by  Aristotle. f 
The  breathing-tubes  all  run  into  what  may  be  called  a 
wind-pipe,  one  of  which  lies  along  each  side  of  the 
insect;  and  these  two  wind-pipes  send  off  innumerable 
small  branches  with  aij;  to  the  vessels  containing  the 
digested  food,  supplying  it  with  oxygen  for  the  pur- 
poses of  nourishment.  A  fluid  is  thus  prepared  ana- 
logous to  the  blood  of  the  larger  animals,  and  stored 
up  in  a  large  dorsal  vessel;  but  this  is  not  at  all  like 
a  heart,  for  though  it  has  been  observed  to  beat,  its 
motions  do  not  seem  to  be  constant  or  regular,  and 
no  blood-vessels  go  off  from  it.  The  fluid  analogous 
to  blood  may  perhaps  pass  through  this  singular  reser- 
voir, as  water  does  through  blotting-paper;  but  as  yet 
this  process  has  not  been  accurately  investigated.  A 
more  distinct  notion,  however,  of  the  process  of  insect 
breathing  may  be  obtained  from  Swammerdam's  sketch 
of  the  interior  of  the  water-grub  of  a  May-fly  (Ephe- 
mera). 

It  is  further  conjectured  that  the  portion  of  the  blood 
not  immediately  wanted  for  nourishing  the  organs  al- 
ready formed,  goes  to  form  a  mass  of  thickish  muci- 
lage, contained  in  floating  membranes  of  a  white,  yel- 

*  Insect  Archi.,  p.  303.       t  Aristotle,  Hist.  Animal.,  viii,  27. 


WATER    GRUB    OF    A    MAY-FLY. 


139 


Dissection  of  the  water-grub  of  a  May-fly  (Ephemera).  The  back 
is  laid  open,  and  the  nerves,  intestines,  and  respiratory  apparatus 
exhibited,  aaaaaa,  six  clusters  of  short  tubes,  opening  on  both 
sides,  through  which  the  creature  breathes:  the  air  contained  in  the 
water,  passing  through  these,  enters  two  wind-pipes,  bhb  b,  running 
from  head  to  tail,  and  circulates  through  every  part  of  the  body.  The 
eight  flns,  and  a  portion  of  the  tail  bristles  have  been  omitted,  to  give 
the  rest  of  the  figure  on  a  larger  scale.  The  central  white  lines  are 
the  nerves. 


140  INSECT    TRANSFORMATIONS. 

low,  or  green  colour,  and  apparently  analogous  to  fat 
in  the  larger  animals.*  This  furnishes,  as  is  further 
supposed,  a  store  of  nutriment  for  promoting  the  growth 
of  the  butterfly.! 

This  brief  sketch  will  serve  to  give  the  reader  a  tole- 
rable notion  of  the  internal  structure  of  caterpillars,  and 
the  manner  in  which  their  food  is  elaborated  into  nutri- 
ment; but  when  we  know  that  Ljonnet  wrote  a  large 
quarto  volume  on  the  structure  of  a  single  caterpillar, 
and  that  Malpighi,  Heroldt,  Ramdohr,  Sprengel,  and 
Marcel  de  Serres,  are  little  less  voluminous,  it  will  be 
understood  that  we  give  it  merely  as  a  sketch  which 
we  could  easily  have  extended,  had  it  appeared,  as  it 
does  not,  to  be  suitable  to  our  plan.  It  will  prove  more 
interesting,  we  think,  to  pass  now  to  the  external  struc- 
ture and  appearance. 

It  will  be  obvious  from  what  we  have  said  respect- 
ing the  colours  of  eggs,  that  we  are  not  inclined  to 
adopt  in  all  its  extent  the  theory  of  many  naturalists, 
which  maintains  the  peculiar  colours  and  forms  of  ani- 
mals to  be  given  them  by  nature  for  the  purpose  of 
concealment  from  their  enemies.  As  in  the  instance 
of  caterpillars  this  theory  meets  us  again  in  full  force, 
we  shall  mention  a  few  facts  which  appear  not  only  to 
be  at  variance  with  it,  but  show,  we  think,  that  the 
facts  of  the  theorists  may  stand  as  appropriately  for 
exceptions  as  for  a  general  rule.  Since  caterpillars 
form  the  staple  food  of  soft-billed  birds  and  of  the 
young  of  most  hard-billed  birds,  not  to  mention  the 
parasite  grubs  of  ichneumon-flies  which  destroy  great 
numbers,  nature  has  provided  an  immense  abundance 
of  them,  beyond  what  is  requisite  for  continuing  the 
race.  Were  it  maintained,  therefore,  that  they  were 
all  by  design  so  formed  and  coloured  as  to  deceive  the 
eyes  of  birds  and  ichneumons,  the  purpose  of  their 

*  Lyonnet,  Anat.  de  !a  Chenille,  106. 
"i    Reaumur,  Mem.  i,  145. 


COLOURS  AND  FORMS  OF  INSECTS.      141 

superabundant  production  would  be  frustrated.  We 
have  no  doubt,  indeed,  that  insectivorous  animals  can 
instinctively  detect  their  prey,  in  all  the  usual  modes  of 
concealment,  as  acutely  as  the  practised  eye  of  a  na- 
turalist, who  can  with  ease  perceive  what  escapes  the 
observation  of  the  inexperienced.  When  a  woodpeck- 
er is  taught  by  nature  to  detect  a  wood- boring  cater- 
pillar, by  the  bark  sounding  hollow  when  tapped  with 
his  bill,  and  when  an  ichneumon  fly  can  detect  a  chry- 
salis closely  rolled  up  in  a  leaf,*  we  should  be  strongly 
inclined  to  doubt  that  colour  or  form  could  afford  very 
effectual  concealment  from  enemies,  though  we  readily 
grant  that  many  probable  instances  of  this  have  been 
adduced.  Of  these  instances  it  may  be  well  to  give 
a  few  examples. 

The  caterpillar  of  a  nocturnal  moth  (Noctua  algce, 
FABR.)  is  said  to  assume  the  colour  of  the  lichens 
upon  which  it  feeds,  being  gray  when  it  feeds  on  a 
gray  one  (Parmelia  saxatilis,  ACH.),  and  always  yel- 
low when  it  feeds  on  a  yellow  one  (Cctraria  juni- 
perina,  ACH.);|  the  change  of  colour  being  (it  is 
alleged)  intended  by  Providence  to  conceal  it  from 
its  enemies,  as  it  becomes  difficult  to  distinguish  it 
from  the  lichens.  The  caterpillar  of  the  coronet  moth 
(Jlcronycta  Ligustri,  OCHSENHEIM.),  which  feeds 
upon  the  privet,  is  so  exactly  of  the  colour  of  the  un- 
derside of  the  leaf,  to  which  it  usually  clings  during 
the  day,  that  a  person  may  have  the  leaf  in  his  hand 
without  discovering  the  caterpillar ;J  a  circumstance 
explained  upon  the  same  principle.  This,  indeed,  is 
no  common  circumstance,  as  many  caterpillars 
very  nearly  resemble  the  colour  of  the  leaves  upon 
which  they  feed  ;  and  the  wonder  rather  is,  that  so 

*  See  { Insect  Architecture,5  p.  174-5. 

t  Fabr.  Vorlesung.  in  Kirby  and  Spence,  ii,  220. 

j:  Brahm,  Insecten,  in  ibid,  p.  221. 


14  INSECT    TRANSFORMATIONS. 

many  others  should  not  be  similarly  coloured,  when 
we  consider  that  their  stomachs  occupy  the  greater 
portion  of  their  bodies,  arid  are  generally  gorged  with 
food.  It  would  be  no  difficult  matter,  therefore,  to 
enumerate  several  hundred  examples  of  caterpillars 
resembling  in  colour  the  substances  upon  which  they 
feed.  It  strikes  us  as  more  singular  to  find  a  great 
many  which,  though  they  feed  on  green  leaves,  re- 
semble in  colour  the  gray  or  brown  bark  of  the 
branches  where  they  usually  rest  when  not  feeding 


Caterpillars  of  the  Clifden  nonpareil  feeding  on  the  gray  poplar. 

A  marked  instance  of  this  occurs  in  the  caterpillar  of 
one  of  our  largest  and  most  beautiful  moths,  the  Clif- 
den nonpareil  ( Catocala  fraxini,  SCHRANK),  which 
feeds  on  the  ash  and  the  poplar,  and  is  so  similar  to 
a  stripe  of  brown  lichen  dotted  with  black,  that  it 
would  not  be  readily  discovered  by  any  person  but  a 
naturalist.* 

*  J.  R. 


COLOURS    AND    FORMS    OF    INSECTS.  143 


Caterpillars  of  the  Clifden  nonpareil  in  a  more  advanced  stage  of  growth. 

Of  the  extraordinary  tropical  insects  popularly 
termed  Walking-leaves,  belonging  to  several  orders 
and  families  (Locusta,  Mantis,  Phasma,  <$rc),  the 
wing-cases,  not  only  in  colour,  but  in  texture,  and 
even  in  veining,  are  so  exactly  like  leaves,  from  the 
fresh  green  of  those  newly  expanded  to  the  faded 
brown  of  those  withered  and  fallen,  that  botanists 
themselves  might  be  deceived  if  they  were  detached 
from  the  insects  and  exhibited  as  real  leaves.  Among 
the  locusts  of  Fabricius  ( Pterophylla,  KIRBY)  alone, 
we  find  the  various  species  with  wing-cases  resembling 
in  this  manner  the  leaves  of  the  laurel,  the  myrtle,  the 
citron,  the  lily,  the  sage,  the  olive,  the  camellia,  thyme, 
and  grass. 

The  Spectres  (Phasmatce,  LICHTENSTEIN),  on  the 
other  hand,  resemble  the  smaller  branches  of  trees 
with  their  spray;  and  so  minutely  detailed  is  this  mi- 
micry that  the  very  snags  and  knobs,  as  Kirby  and 
Spence  remark,  are  accurately  imitated.  Those  who 
are  curious  in  such  matters  may  readily  find  similar 
instances  in  some  of  our  native  caterpillars,  by  no 
means  uncommon.  Tn  the  latter  part  of  summer,  for 
example,  by  beating  the  bushes  of  a  hawthorn  hedge 
while  an  umbrella  is  held  under,  the  caterpillar  of  the 
brimstone  moth  (Rumia  Cralccgata  ?  DUPONCHET) 
may  often  be  found,  appearing,  as  it  stalks  along  the 


144  INSECT    TRANSFORMATIONS. 


Walking-leaf  insect  (Phyllia  foliata,  Dumeril),  magnified. 

whalebones  of  the  umbrella,  like  a  self-moving  withered 
branch,  the  skin  being  wrinkled  and  furrowed  like  the 
bark,  while  the  bulgings  of  the  rings  and  a  notched 
protuberance  on  the  back  add  much  to  the  resem- 
blance. 


COLOURS    AND    FORMS    OF    INSECTS. 


145 


Transformations  of  the  brimstone  moth  . 

c,  Ihe  caterpillar  in  its  resting  position.   6,  the  m*>£h.   c,  the  eggs. 
tZ,  the  young  caterpillar. 

We  found  during  last  summer,  on  an  elder,  at  Lee, 
several  specimens  of  a  similar  walking-branch  cater- 
pillar, that  of  the  swallow-tail  moth  (Ourapteryx 
Sambucaria,  LEACH),  not  so  common  as  the  preced- 
ing, but  equally  remarkable;  for  the  ringed  bulgings 
on  the  body  are  precisely  like  those  of  an  elder  branch, 
while  the  longitudinal  stripes  are  like  the  cracks  in 
the  bark.*  It  is  likewise  worthy  of  remark  that  these 
caterpillars,  when  not  feeding,  rest  upon  their  pro- 
legs,  with  their  body  stretched  out  at  various  angles 
from  the  branch,  their  only  support  being  a  thread  of 


VOL.    TK 


*  J.  R. 
13 


146 


INSECT    TRANSFORMATIONS. 


silk,  from  which  the  head  hangs,  in  order  that  they  may 
always  be  ready  to  drop  down  in  safety,  by  extending 
this  thread,  on  the  sudden  approach  of  enemies.  As 
they  feed  chiefly  in  the  night,  they  may  be  seen  con- 
tinuing in  this  stiff  and  singular  attitude  for  a  whole 
day  without  moving,  <  So  that,  doubtless,'  say 
Kirby  and  Spence,  '  the  sparrows  and  other  birds 
are  frequently  deceived  by  this  manoeuvre,  and  thus 
baulked  of  their  prey.  Rh'sePs  gardener,  mistaking 
one  of  these  caterpillars  for  a  dead  twig,  started  back 
in  great  alarm,  when  upon  attempting  to  break  it  he 
found  it  was  a  living  animal.'*  We  are  well 


Caterpillars  of  the  swallow-tailed  moth,  resembling  the  twigs  on 
which  they  rest. 

*  Intr.  ii,  236;  Rc'sel,  Insecten,  i,  v.  27. 


COLOURS  AND  FORMS  OF  INSECTS.      147 

persuaded,  however,  that  neither  a  bird,  an  ichneu- 
mon, nor  a  naturalist,  would  have  been  apt  to  fall  into 
such  a  mistake. 

This  family  of  caterpillars  (Geometridce,  STEPHENS) 
have  been  by  collectors  not  inappropriately  named 
surveyors,  loopers,  and  geometers,  from  their  peculiar 
manner  of  moving,  which  may  readily  be  conceived 
by  those  who  have  not  seen  them,  when  we  mention 
that  at  the  commencement  of  each  step  their  bodies 
present  a  pretty  exact  figure  of  the  Greek  letter  tt. 
In  this  position,  laying  hold  with  their  hinder  prolegs, 
they  stretch  out  their  heads  to  the  full  extent  of  their 
body,  laying  hold  with  their  fore  legs  while  they  bring 
forward  their  body  into  the  £1  form  again. 

Such  are  among  the  most  prominent  examples  ad- 
duced by  naturalists  who  advocate  the  theory  that 
these  resemblances  to  inanimate  objects  are  intended 
to  conceal  insects  from  their  enemies.*  We  shal/ 
now  give  a  few  instances  which  have  suggested 
themselves  as  no  less  corroborative  of  the  opposite 
doctrine.  The  first  which  occurs  to  us  is  one  of  the 
surveyor  caterpillars,  whose  movements  we  have  just 
been  describing,  found  very  commonly  on  the  cur- 
rant, the  gooseberry,  and  the  black  thorn,  and  called 
by  collectors  the  magpie  (Jlbraxas  Grossulariata, 
LEACH.)  This  caterpillar  is  very  conspicuous  from 
being  spotted,  somewhat  like  the  perfect  insect,  with 
black  upon  a  bright  yellow  ground,  and  contrasting 
strongly  both  with  the  deep  green  of  the  leaves  upon 
which  it  feeds,  and  the  dark-coloured  bark  upon 
which  it  usually  rests.  The  caterpillars  of  the  water 
betony  moth  (CucuUia  Scrophularice,  HUBNER), 
and  of  the  burnet  moth  (Euclidia  Glyphica,  OCH- 
SEiNHEiM.),  are  similarly  marked  with  deep  black  on  a 
yellow  ground,  which  must  render  them  very  conspi- 
cuous. The  caterpillars  of  the  small  tortoise-shell 

*  See  Kirby  and  Spence,  Intr,  ii,  219-237. 


148  INSECT    TRANSFORMATIONS. 

butterfly  (Vanessa  fTr/icce),  are,  we  admit,  very  simi- 
lar in  colour  to  the  nettles  they  are  found  on ;  but  we 
cannot,  surely,  say  the  same  of  the  dark  black  ones 
of  the  peacock  (V.  Jo),  also  nettle  feeders,  particu- 
larly as  these  are  not  only  large,  but  keep  together  in 
numerous  companies;  which  also  applies  to  the  cater- 
pillar of  the  Camberwell  beauty  (  V.  Jlnliopa\  as 
well  as  to  the  conspicuous  caterpillar  of  the  buff  tip 
(Pygcera  bucephala,  OCHSENH.),  so  very  destructive 
in  certain  years  to  beeches,  oaks,  limes,  filberts,  and 
other  trees.*  Some  of  those  just  mentioned,  indeed, 
are  provided,  as  we  shall  afterwards  see,  with  better 
means  of  defence  than  their  colours;  but  if  peculiar 
colours  be  given  by  nature  for  the  purpose  of  conceal- 
ment, as  in  the  instance  of  the  caterpillars  of  the 
small  tortoise-shell,  why  are  these  studded  with  thorns 
in  the  same  way  as  the  conspicuous  caterpillars  of  the 
peacock  and  the  Camberwell  beauty  ?  In  this,  as 
in  many  other  instances,  the  theory  evidently  proves 
too  much. 

To  the  examples  which  we  have  here  given  of 
conspicuous  caterpillars,  we  could  easily  add  some 
hundreds  more;  but  thinking  these  sufficient,  we 
may  be  permitted,  by  way  of  farther  illustration,  to 
allude  to  the  instances  remarkable  in  perfect  insects. 
Kirby  and  Spence  mention  a  different  kind  of  imita- 
tion of  form  and  colour,  which  they  think  f  affords  a 
beautiful  instance  of  the  wisdom  of  Providence  in 
adapting  means  to  their  end.'  One  of  those  two- 
winged  flies  (Vblucellce,  GEOFFROI),  which  bear  a 
considerable  resemblance  to  humble  bees,  lives  during 
the  larva  state  in  the  hives  of  the  latter;  and  it  is 
inferred,  that  as  the  flies  '  strikingly  resemble  those 
bees  in  shape,  clothing,  and  colour,  the  Author  of 
nature  has  provided  that  they  may  enter  these  nests 

*  All  these  caterpillars  are  figured  in  this  volume:  see  con- 
tents of  the  engravings. 


COLOURS    AND    FORMS    OF    INSECTS.  149 

and  deposit  their  eggs  undiscovered;'  for  'did  they 
venture  themselves  amongst  the  humble  bees  in  a  less 
kindred  form,  their  lives  would  probably  pay  the  for- 
feit of  their  presumption.'* 


A  two-winged  fly  (f'olucella  plumat a,  Meigen.) 

We  do  not  conceive  that  any  dissent  from  this  doc- 
trine has  a  tendency  to  weaken  or  destroy  the  smal- 
lest link  in  the  beautiful  chain  of  causes  which 
leads  us  upwards  to  the  admirable  superintendence 
of  the  great  First  Cause;  and,  therefore,  we  state 
that,  in  the  case  before  us,  our  justly  eminent  authors 
surely  forgot,  that  bees  well  know  strange  individuals 
of  their  own  species,  and  beat  them  off  when  they 
attempt  to  plunder  their  hives;  and  these  robber  bees 
are  not  only  like  but  identical  with  themselves  in  shape, 
clothing,  and  colour.  Indeed,  when  it  is  considered 
that  in  the  designs  of  Providence,  as  evidenced  by 
the  economy  of  nature,  the  nourishment  of  the  stron- 
ger species  of  carnivorous  animals  is  as  much  regard- 
ed as  the  means  which  the  weaker  have  of  escap- 
ing from  them,  such  general  rules  cannot  be  but  of 
very  limited  application. 

Darwin,  as  we  formerly  mentioned,  maintained  that 
butterflies  resembled  the  colours  of  the  flowers 
which  they  frequent;  and  many  of  them  may  be 

*  Intr.  ii,  223. 
VOL.     VI.  13* 


150  INSECT    TRANSFORMATIONS. 

granted  to  do  so  without  leading  us  to  adopt  the 
inference  of  the  theorists  that  they  are  thus  coloured 
to  conceal  them  from  their  enemies.  Were  this,  in- 
deed, the  true  cause  of  these  colours,  the  butterflies 
ought  to  remain  stationary  on  the  flowers,  without 
sporting  about  in  the  sunshine,  as  if  on  purpose  to 
show  the  birds  and  the  dragon  flies  that  they  are 
living  insects,  and  not  inanimate  flowers.  In  the 
instance  of  many  moths  which  fly  by  twilight,  this  is 
no  less  obvious;  for  instead  of  being  of  dark  dusky 
colours,  which  would  have  effectually  concealed  them 
from  the  bats  and  the  fern-owls,  they  are  frequently 
white,  or  at  least  of  such  light  colours  as  show  well 
in  the  dusk.  There  is  but  small  need  of  enumera- 
ting examples  of  this,  and  it  will  be  sufficient  to  name 
the  white-ghost  moth  (Hepialus  Humility,  which  may 
often  be  seen,  where  hops  or  burdocks  grow,  hovering 
on  the  wing  for  hours  together;  the  satin  moth  (Leu- 
coma  SaliciSy  STEPHENS),  which  floats  about  the 
air  like  an  animated  flake  of  snow-white  down,  or 
flits  conspicuously  from  tree  to  tree  among  the  higher 
branches  of  a  row  of  poplars;  and  the  magpie  moth 
(Jlbraxas  grossulariata),  usually  abundant  in  every 
garden,  though  liberally  sprinkled  with  black  spots, 
has  enough  of  white  to  distinguish  it  in  its  heavy, 
lumbering  flight,  even  when  the  last  rays  of  the  twi- 
light are  disappearing.  That  these  are  not  strained 
examples  of  insects  so  coloured  as  to  be  conspicuous 
to  their  enemies,  will  farther  be  obvious  from  a  common 
contrivance  of  schoolboys  to  catch  bats.  They  chalk 
the  seed-heads  of  burdocks  in  such  a  manner  as  to 
resemble  the  white  moths  alluded  to;  and  throwing 
these  up  where  a  bat  is  observed  fbing,  he  fails  not 
to  dart  upon  the  supposed  moth,  and  the  bur  adher- 
ing to  his  wings,  brings  him  down  to  pay  the  penalty 
of  his  mistake.* 

*  J.  R. 


COLOURS    AND    FORMS    OF    INSECTS.  151 

If  we  leave  colouring  out  of  consideration,  and 
look  merely  at  the  forms  of  caterpillars,  we  think  it 
must  be  apparent  to  the  most  indifferent  observer, 
that,  though  they  have  often  a  rather  ungainly, 
repulsive,  and  sometimes  a  formidable  aspect,  yet 
this  renders  them  in  numerous  instances  very  conspi- 
cuous. The  forms,  also,  we  may  remark,  which  ap- 
pear disagreeable  or  threatening  to  us,  may  not  seem 
so  to  birds  and  ichneumons  which  make  them  their 
prey.  One  of  the  most  singular  of  these  forms  of 
caterpillars  occurs  in  that  of  the  pebble  moth  (JVbfo- 
donta  Ziczac,  STEPHENS),*  the  form  being  such  that 
it  is  not  easy  for  one  unacquainted  with  it  to  tell  which 
is  the  head  and  which  the  tail.  The  puss  ( Cerura 
Vinula)  is  another  whose  form  and  attitudes  cannot 
fail  to  attract  the  notice  of  the  most  indifferent  obser- 
ver. Dr  Shaw,  in  his  Zoological  Lectures,  quotes 
from  a  country  newspaper  a  most  ludicrous  account  of 
this  '  monster,'  as  it  is  there  called,  having  a  head 
like  a  lion,  jaws  like  a  shark,  a  horn  like  a  unicorn, 
and  two  tremendous  stings  in  its  tail.  The  gross  ex- 
aggeration of  this  description  will  be  obvious  from  the 
following  accurate  figures;  yet  how  formidable  soever 
this  caterpillar  may  appear  to  us  (even  Rosel,  the 
entomologist,  was  afraid  of  it  at  first),  we  know  that 
no  one  is  more  readily  pounced  upon  by  at  least  two 
species  of  ichneumons,  which  §eem,:  therefore,  not  to 
be  afraid  to  deposit  their  eggs  in  its  body;f  and  it  is 
no  doubt  often  made  prey  of  by  birds,  at  least  in  its 
young  state;  for  when  full  grown,  being  about  as 
thick  as  a  man's  thumb,  it  may  prove  rather  too 
bulky  a  morsel. J 

Our  readers  may  like  to  see,  by  way  of  contrast 
to  the  exaggerated  account  quoted  by  Shaw,  the 
excellent  description  of  the  puss  caterpillar  given 

*  Figured  in  Insect  Architecture,  p.  172. 

f  See  ibid,  pp.  195,  and  325-6.  J  J.  R. 


152 


INSECT    TRANSFORMATIONS. 


by  old  Isaac  Walton.  i  The  very  colours  of  caterpil- 
lars,' says  he,  '  as  one  has  observed,  are  elegant  and 
beautiful.  I  shall,  for  a  taste  of  the  rest,  describe 
one  of  them;  which  I  will,  some  time  the  next  month, 
show  you  feeding  on  a  willow  tree;  and  you  shall 
find  him  punctually  to  answer  this  very  descrip- 
tion: his  lips  and  mouth  somewhat  yellow;  his  eyes 


Transformations    of  the  puss   moth    (Centra    Vinula).    a,   the   egg. 
6-56,  young  larvse.    c,  full-grown  larva.     <i,  the  pupa,   e,  the  moth. 


COLOURS    AND    FORMS    OF    INSECTS.  153 

black  as  jet;  his  forehead  purple;  his  feet  and  hinder 
parts  green;  his  tail  two-forked  and  black;  the  whole 
body  stained  with  a  kind  of  red  spots,  which  run 
along  the  neck  and  shoulder-blade,  not  unlike  the  form 
of  St  Andrew's  cross,  or  the  letter  X  made  thus 
crosswise,  and  a  white  line  drawn  down  his  back  to 
his  tail;  all  which  add  much  beauty  to  his  whole  body. 
And  it  is  to  me  observable,  that  at  a  fixed  age  this 
caterpillar  gives  over  to  eat,  and  towards  winter 
comes  to  be  covered  over  with  a  strange  shell  or  crust, 
called  an  aurelia;*  and  so  lives  a  kind  of  dead  life 
without  eating  all  the  winter.  And  as  others  of  seve- 
ral kinds  turn  to  be  several  kinds  of  flies  and  vermin 
the  spring  following;  so  this  caterpillar  then  turns  to 
be  a  painted  butterfly.'')' 

Another  caterpillar,  called  by  collectors  the  lobster 
(Slauropus  Fagi,  GERMAR.),  which  is  rarely  met 
with,  has  not  only  very  long  legs,  a  circumstance  un- 
common among  caterpillars,  but  assumes  an  attitude 
similar  to  the  puss  just  figured,  though  the  shape  of 
the  creature  renders  it  much  more  strange.  This 
caterpillar  was  known  to  Mouffet,  and  is  indifferently 
figured  by  him,  as  well  as  by  Albin  and  Donovan; 


Lobster  caterpillar  (Stauropus  Fagi,  Germar.) 

*  See  Insect  architecture,  p.  194. 
t  Walton's  Angler,  chap.  v. 


154  INSECT    TRANSFORMATIONS. 

but  Rosel's  figure,  which  we  here  copy,  is  more  ac- 
curate. 

Looking  at  these  very  singular  forms  of  caterpil- 
lars, we  could  not  anticipate,  without  previous  know- 
ledge, that  all  of  them  produced  insects  of  nearly  the 
same  shape,  though  differing  considerably  in  size  and 
colour.  It  is  not  a  little  remarkable,  also,  that  the 
colours  of  caterpillars,  with  a  few  exceptions,  such  as 
the  magpie  moth  (Mraxas  grossulariata),  are  very 
different  indeed  from  the  insects  into  which  they  are 
transformed.  Plain  and  inconspicuous  caterpillars 
will  sometimes  give  splendidly  coloured  insects,  as  in 
the  case  of  the  Vanessa  butterflies;  while  finely  mark- 
ed caterpillars  will  give  plain  insects,  as  the  one  whose 
gaudy  stripes  of  sky-blue,  scarlet,  and  black,  has  ob- 
tained it  the  appropriate  name  of  the  lackey  (  Clisio- 
campa  neustria,  CURTIS),  though  the  moth  is  of  a 
dull  brownish  yellow.  Two  of  our  finest  native  in- 
sects, however,  the  swallow-tailed  butterfly  and  the 
emperor-moth,  are  produced  from  beautifully  coloured 
caterpillars;  but  neither  the  colours  nor  the  .markings 
of  these  have  any  resemblance. 

A  more  extraordinary  difference,  however,  between 
the  first  and  the  last  stage  of  insect  life  occurs  in  the 
case  of  those  insects  whose  larvse  are  aquatic.  One 
of  our  commonest  families  of  insects,  the  gnats  (Cw- 
licidce,  LATR.),  whose  ingenious  mode  of  construct- 
ing a  floating  raft  of  eggs  we  have  already  described, 
affords  a  very  striking  illustration  of  our  position. 
When  these  eggs  are  hatched,  the  grubs  appear;  but 
they  do  not,  as  is  said  by  older  naturalists,  <  make 
themselves  little  lodgments  of  glue,  which  they  fasten 
to  some  solid  body  at  the  very  bottom  of  the  water, 
unless  they  meet  with  chalk,  whose  softness  permits 
them  to  burrow  into  its  substance.'*  On  the  contra- 

*  Spectacle  de  la  Nature,  i,  123. 


ORGANS    FOR    BREATHING    IN    WATER-GRUBS.    155 

ry,  they  usually  swim  near  the  surface  of  the  water,  with 
their  heads  downwards  and  their  tails  in  the  air,  for  a 
purpose  which  will  presently  be  obvious.  These  grubs, 
called  scurrs  in  the  north,  may  be  met  with  in  abun- 
dance during  the  summer  in  ditches  or  in  water- 
butts,*  appearing  like  minute,  whitish  semi-transpa- 
rent shrimps  or  fishes,  when  their  bodies  are  a  little 
bent,  as  they  frequently  are. 


Aquatic  grubs  of  gnats  in  a  glass  vessel  of  water. 

The  organs  for  breathing,  which  are  very  remark- 
able in  the  grub  of  the  gnat,  are  not  situated  along 
the  sides,  as  in  caterpillars,  but  in  the  tail.  A  tube 
for  the  purpose  of  respiration  goes  off  from  the  termi- 
nal ring  of  the  body  at  an  angle.  Its  main  buoys, 
also,  are  its  tail  and  its  breathing-tube,  both  of  which 
end  in  a  sort  of  funnel,  composed  of  hairs,  in  form  of 
a  star,  anointed  with  oil,  so  as  to  repel  water.  Swam- 
merdam  remarks  that  when,  by  handling  it  too  rough- 
ly, this  oil  is  removed,  the  grub  *  can  no  longer  sus- 
pend itself  on  the  surface  of  the  water;  I  have,  on  these 
occasions,  observed  it  put  its  tail  in  its  mouth,  and 
afterwards  draw  it  back,  as  a  water-fowl  will  draw 
its  feathers  through  its  bill  to  prepare  them  for  resist- 

*  See  Insect  Architecture,  p.  20,  bottom  figure,  on  the  right- 


156 


INSECT    TRANSFORMATIONS. 


ing  water. '*  The  air,  which  enters  through  several 
openings  in  the  breathing-tube,  passes  onwards  to  two 
lateral  wind-pipes,  very  similar  to  those  of  caterpil- 
lars, as  above  described.  When  it  wishes  to  descend 
to  the  bottom  of  the  water,  it  folds  up  the  hairs  of  the 
funnel,  but  by  means  of  its  oil  retains  at  their  ends  a 
globule  of  air;  and  when  it  wishes  to  re- ascend,  it  has 
only  to  open  its  hair  funnel  again. 


Larva  of  the  common  gnat  (Culcx  Viflitns?)  floating  in  water, 
greatly  magnified,  a  a,  the  body  and  head  of  the  larva.  6,  the 
respiratory  apparatus,  situated  in  the  tail,  c,  the  larva  not  mag- 
nified, 

A  similar  but  more  elegant  apparatus  for  the  same 
purpose  occurs  in  the  water-grub  of  a  two-winged  fly, 
which  Goedart  called  the  chamelion  fly  ( Straiiomys 
chamczleon,  MEIGEN),  because  he  found  it  could 
live  nine  months  without  food.  The  terminal  ring  of 
this  grub  is  extended  to  a  considerable  length,  and 
fringed  at  the  end  with  a  beautiful  star  like  funnel  of 
thirty  feathered  hairs.  Whether  the  creature  oils  these, 

*  Biblia,  Naturae,  i,  154. 


ORGANS    FOR    BREATHING    IN    WATER-GRUBS.      157 

like  the  grub  of  the  gnat,  we  know  not,  hut  they 
perfectly  repel  water  ;  and  at  the  point  where  the 
insect  hangs  suspended,  a  small  dimple  may  be  ob- 
served on  the  surface.  When  it  wishes  to  dive  to  the 
bottom,  it  has  the  power  of  bringing  the  ends  of  the 
hairs  together,  without  diminishing  the  capacity  of  the 
funnel  below  ;  and  a  globule  of  air,  for  the  purpose  of 
breathing  under  water,  is  thus  enclosed  and  carried 
down,  appearing,  as  Swammerdam  says,  like  a  bril- 
liant pearl  or  polished  silver.  c  As  for  my  part,'  he 
adds,  <  I  dare  boldly  affirm,  that,  the  incomprehensible 
greatness  of  the  Deity  manifests  itself  in  these  mys- 
terious operations  in  a  particular  manner,  and  affords 
us  an  opportunity  of  examining,  as  it  were,  with  our 
senses,  the  divine  nature.'* 


Buoy  like  structure  in  the  tail  of  a  water-grub  of  a  two-winged  fiy. 

' 


VOL.    VI. 


Swammerdam,  part  ii,  51. 
14 


158  INSECT    TRANSFORMATIONS. 

The  preceding  grub  may  occasionally  be  found  in 
shallow  ditches,  and  about  the  edges  of  ponds,  in 
summer;  but  a  remarkable  larva,  with  a  very  dif- 
ferent apparatus  for  breathing,  is  much  more  common 
in  similar  situations,  and  also  in  the  open  drains  from 
dunghills,  &c.  The  latter  is  the  maggot  of  a  two- 
w,inged,  bee-like  fly  (Helophilus pendulus,  MEIGEN), 
and  from  its  shape  is  appropriately  termed  rat-tailed 
by  Reaumur.  The  tail  is  the  part  of  the  grub  which 
most  merits  attention,  being  formed  somewhat  after  the 
telescopic  model  of  the  ovipositor  of  the  breeze  flies,* 


a  bc 

Telescopic-tailed  water  larvae,  n,  a  glass  vessel  of  water  containing 
the  larvae,  natural  size,  i,  magnified  view  of  the  tail,  with  the  breath- 
ing tube  partially  contracted,  c,  a  still  more  enlarged  view  of  the  tail. 

*  See  Insect  Architecture,  p.  403. 


ORGANS    FOR    BREATHING    IN    WATER-GRUBS.    159 

but  consisting  only  of  two  tubes,  the  outer  one  serv- 
ing as  a  sheath,  within  which  the  inner  one  can  be 
retracted  at  pleasure.  Both  of  these  are  composed  of 
fibrous  rings;  and  are  so  very  extensile,  that  R  aumur 
has  seen  them  pushed  out  to  twelve  times  the  length 
of  the  body  of  the  maggot.  The  contrivance  by  which 
the  inner  tube  is  pushed  out  is  no  less  simple  than 
ingenious.  It  is  furnished  at  the  base  with  two 
flexible  pipes,  coiled  up,  when  it  is  sheathed,  into 
several  folds,  and  communicating  with  the  double 
wind-pipe  ( Trachea}  in  the  body.  When  it  wishes 
to  extend  this  breathing-tube,  therefore,  it  inflates,  by 
means  of  air  from  the  wind-pipe,  the  flexible  pipes, 
and  in  this  way  pushes  them  outward,  and  with  them 
the  breathing-tube,  to  the  extent  required.  The 
breathing-tube  itself  is  very  slender,  but  terminates 
similarly  to  those  of  the  grub  of  the  chameleon  fly,  in 
five  bristles.  This  breathing  apparatus  is  admirably 
adapted  to  the  economy  of  these  maggots  ;  as  from 
their  seeking  their  food  amongst  ooze  and  mud,  they 
would  often  be  exposed  to  suffocation,  which  their 
extensile  tube  effectually  prevents. 


Water  worms  (Nais).    a  a  a,   half-concealed  in  the  sand. 
bbb,  their  sand-tubes  exposed. 


160  INSECT    TRANSFORMATIONS. 

It  may  not  be  improper  to  guard  our  younger  read- 
ers against  mistaking  for  these  telescopic-tailed  larvae, 
an  animal,  found  in  the  same  situations,  which  has  a 
considerable  general  resemblance  to  them,  though 
it  is  not  even  an  insect,  but  a  water-worm  (JV</is),  up- 
on which  Bonnet  made  numerous  curious  experiments. 
The  nais  may  be  easily  known  by  its  being  reddish, 
while  the  maggot  is  of  a  dirty  white  colour. 

It  appears  to  be  the  nais,  or  some  similar  fresh-wa- 
ter worm,  which  medical  men,  unacquainted  with  na- 
tural history,  have  supposed  to  get  into  the  human 
stomach  through  the  medium  of  water,  as  we  shall 
presently  notice. 

A  no  less  singular  structure  for  respiration  than  that 
just  described,  occurs  in  the  aquatic  larvae  of  the 
dragon-flies  Libellulidce,  LEACH),  which  differs  so 
remarkably  from  the  perfect  insects  in  the  beauty  of 
colour  and  elegance  of  form  that  has  procured  for 
them  the  gallant  appellation  of  damsels  (demoiselles) 
in  France.  This  title  agrees  as  badly  with  their 
habits  as  the  popular  English  name  of  horse-simmers  ^ 
since  they  have  no  apparatus  for  stinging  ;  *  and  so 
far,'  says  R  >aumur,  '  from  seeking  an  innocent  nutri- 
ment in  the  pulp  of  fruits,  or  the  nectar  of  flowers, 
they  are  more  like  amazons  than  damsels,  hovering 
in  the  air  only  to  pounce  upon  other  insects,  which 
they  crush  with  their  powerful  mandibles.  Should 
they  quit  the  margin  of  a  pond  or  the  banks  of  a 
rivulet,  where  they  may  be  seen  hawking  about  in 
multitudes,  it  is  only  to  pursue  and  seize  the  moth  or 
the  butterfly,  that  has  fled  for  shelter  to  the  bushes.' 

Though  these  larvae  are  furnished  with  six  feet, 
they  not  only  move  very  little,  but  do  not  use  them 
for  walking  so  much  as  for  capturing  their  prey. 
Their  motion  is  effected  by  a  very  peculiar  method. 
When  one  of  these  larvae  is  procured  from  the  bottom 
of  a  pond  or  the  pool  of  a  brook,  let  it  be  put  into  a  large 


STRUCTURE    OF    LARVAE.  161 

saucer  with  water,  with  some  of  the  dead  leaves  or  sticks 
it  previously  employed  as  a  covering;  these  will  soon 
be  seen  floating  towards  the  tail,  and  afterwards  re- 
pelled, as  a  floating  feather  will  be  by  a  stick  of  sealing- 
wax,  or  a  bit  of  amber,  when  electrically  excited.  When 
the  insect  has  been  kept  out  of  the  water  for  a  short 
t'me,  the  desire,  or  necessity,  of  respiration  is  increas- 
ed, and  when  again  put  into  the  water,  the  pumping 
is  repeated  with  unusual  force  and  frequency.  If  it  be 
held  in  the  hand,  head  downwards,  and  some  drops 
of  water  be  let  fall  on  its  tail,  it  instantly  sucks  it  in, 
and  the  dimensions  of  its  body  become  visibly  aug- 
mented; but  it  collapses  again  when  the  water  is  ex- 
pelled, which  is  effected  by  the  same  apparatus. 

While  in  the  water,  if  a  solution  of  cochineal,  saf- 
fron, indigo,  or  any  other  coloured  fluid,  be  let  down, 
with  great  care,  by  means  of  a  glass  tube,  just  over 
the  tail  of  the  insect,  it  will  soon  be  seen  to  eject  a 
stream  of  the  coloured  solution  to  the  distance  of 
several  inches.  Or  the  same  may  be  seen  by  remov- 
ing it  suddenly  out  of  a  coloured  fluid  into  limpid 
water;  when  the  coloured  jet  stream  will  be  still  more 
conspicuous.  The  most  extraordinary  circumstance 
respecting  this  jet  is,  that  it  propels  the  creature 
through  the  water  in  consequence  of  its  being  resisted 
by  the  stationary  mass  of  the  fluid  behind  it,  and  a 
contrary  current  being  thence  produced  by  this  singu- 
lar pumping.  As  the  insect,  between  every  stroke  of 
the  internal  piston,  is  obliged  to  draw  in  a  fresh  sup- 
ply of  water,  #n  interval  consequently  occurs  between 
the  strokes,  during  which  it  will  sometimes  elevate  its 
tail  above  water  and  squirt  out  a  small  stream  like 
that  from  a  little  syringe. 

This  wonderful  apparatus  serves  several  purposes; 
for,  besides  aiding  the  insect  to  move,  the  reverberatory 
current  brings  small  water  insects  within  its  reach: 
it  is  also  it  would  appear,  partly  appropriated  to 

VOL.   vi.  14* 


162 


INSECT    TRANSFORMATIONS. 


respiration,  like  the  gills  of  fish,  though  there  are 
several  other  spiracles  in  other  parts  of  the  body  com- 
municating with  the  large  convoluted  windpipes. 
The  anal  apparatus  is  surrounded  with  five  hard, 
moveable,  triangular  pieces,  all  fringed  with  hairs, 
which  it  can  open  or  shut  at  pleasure.  The  largest 
of  these  pieces  is  placed  above,  while  the  two  smallest 
stand  at  the  sides,  and  two  of  the  middle  size  below. 
When  they  are  shut  close  they  form  a  blunt  cone.* 


a,  grub  of  a  dragon  fly;  b  b,  the  lody  laid  open  and  magnified 
to  show  the  windpipes;  c,  the  pumping  apparatus  shut;  d.  the 
same  open;  e,  head  of  the  insect. 

It  may  not  be  out  of  place  to  take  notice  here  of 
another  singular  structure  in  the  same  species  of  lar- 
vae, which  is  probably  unmatched  in  the  insect  world. 
In  the  larvae  of  most  insects,  the  under-lip  is  small 
and  inconspicuous,  but  in  those  of  the  dragon-flies, 

*  De  Geer,  ii,  666,  and  Reaumur,  vi,  393,  &c. 


STRUCTURE    OF    LARVJE.  163 

( it  is,'  to  follow  the  excellent  description  of  Kirby 
and  Spence,  '  by  far  the  largest  organ  of  the  mouth, 
which,  when  closed,  it  entirely  conceals,  and  it  not 
only  retains  but  actually  seizes  the  animal's  prey,  by 
means  of  a  very  singular  pair  of  jaws  with  which  it  is 
furnished.  Conceive  your  under-lip  (to  have  recourse, 
like  R  aumur  on  another  occasion,  to  such  a  compa- 
rison) to  be  horny  instead  of  fleshy,  and  to  be  elon- 
gated perpendicularly  downwards,  so  as  to  wrap  over 
your  chin,  and  extend  to  its  bottom,  —  that  this  elon- 
gation is  there  expanded  into  a  triangular  convex  plate, 
attached  to  it  by  a  joint,  so  as  to  bend  upwards 
again  and  fold  over  the  face  as  high  as  the  nose,  con- 
cealing not  only  the  chin  and  the  first-mentioned 
elongation,  but  the  mouth  and  part  of  the  cheeks: 
conceive,  moreover,  that  to  the  end  of  this  last-men- 
tioned plate  are  fixed  two  other  convex  ones,  so  broad 
as  to  cover  the  whole  nose  and  temples,  —  that  these 
can  open  at  pleasure  transversely  like  a  pair  of  jaws, 
so  as  to  expose  the  nose  and  mouth,  and  that  their 
inner  edges  where  they  meet  are  cut  into  numerous 
sharp  teeth,  or  spines,  or  armed  with  one  or  more  long 
sharp  claws;  —  you  will  then  have  as  accurate  an 
idea  as  my  powers  of  description  can  give  of  the 
strange  conformation  of  the  under-lip  in  the  larvae  of 
Liibellulina,  which  conceals  the  mouth  and  face  pre- 
cisely as  I  have  supposed  a  similar  construction  of 
your  lip  would  do  yours.  You  will,  probably,  admit 
that  your  own  visage  would  present  an  appearance 
not  very  engaging  while  concealed  by  such  a  mask; 
but  it  would  strike  still  more  awe  into  the  spectators, 
were  they  to  see  you  first  open  the  two  upper  jaw 
plates,  which  would  project  from  each  temple  like  the 
blinders  of  a  horse;  and  next,  having,  by  means  of 
the  joint  at  your  chin,  let  down  the  whole  apparatus 
and  uncovered  your  face,  employ  them  in  seizing  any 


164 


INSECT   TRANSFORMATIONS. 


food  that  presented  itself,  and  conveying  it  to  your 
mouth.  Yet  this  procedure  is  that  adopted  by  the 
larvae  of  the  dragon-fly  provided  with  this  strange 
organ.  While  it  is  at  rest,  it  applies  close  to  and 
covers  the  face.  When  the  insects  would  make  use 
of  it,  they  unfold  it  like  an  arm,  catch  the  prey  at 
which  they  aim  by  means  of  the  mandibuliform  plates, 
and  then  partly  refold  it  so  as  to  hold  the  prey  to  the 
mouth  in  a  convenient  position  for  the  operation  of  the 
two  pairs  of  jaws  with  which  they  are  provided.  Rtau- 
mur  once  found  one  of  them  thus  holding  and  de- 
vouring a  large  tadpole;  a  sufficient  proof  that  Swam- 
merdarn  was  greatly  deceived  in  imagining  earth  to  be 
the  food  of  animals  so  tremendously  armed  and  fitted 
for  carnivorous  purposes.  In  the  larvae  of  Libellula, 
FABR.,  it  is  so  exactly  resembling  a  mask,  that  if  en- 
tomologists ever  went  to  masquerades,  they  could  not 
more  effectually  relieve  the  insipidity  of  such  amuse- 


The  mask  of  the  dragon-fly  grub,  in  four  different  states  of 
opening  and  shutting. 

ments  and  attract  the  attention  of  the  demoiselles  than 
by  appearing  at  the  supper  table  with  a  mask  of  this 
construction,  and  serving  themselves  by  its  assistance. 
It  would  be  difficult,  to  be  sure,  by  mechanism,  to 


STRUCTURE    OP    LARVJE.  165 

supply  the  place  of  the  muscles  with  which  in  the  in- 
sect it  is  amply  provided;  but  Merlin,  or  his  suc- 
cessor, has  surmounted  greater  obstacles.'* 

The  larvee  of  the  dragon-fly  do  not,  however, 
trust  to  this  mask  alone  for  surprising  their  prey,  but 
steal  upon  it,  as  De  Geer  observes,  as  a  cat  does 
upon  a  bird,  very  slowly,  and  as  if  they  counted  their 
steps;  and  then,  by  suddenly  unmasking,  seize  it  by 
surprise:  so  artful  are  they  that  insects,  and  even 
small  fishes,  find  it  difficult  to  elude  their  attacks. f 

The  larva  of  a  very  singular  insect  (Reduvius  per- 
sonatus,  FABR.),  which  preys  upon  the  bed  bug 
(Cimex  lectularius),  not  being  furnished  with  a  mask, 
is  at  the  pains  to  construct  one,  composed  of  dust, 
particles  of  sand,  fragments  of  wool  or  silk,  and  simi- 
lar matter,  which  makes  it  assume  so  very  grotesque  a 
figure,  that  the  animal  would  at  first  be  taken  for  one 
of  the  ugliest  spiders.  Its  awkward  motions  add  not 
a  little  to  the  effect  of  its  odd  appearance.  It  can,  in- 
deed, if  it  so  chooses,  move  with  considerable  speed; 
but  for  the  purposes  of  successful  hunting,  it  endea- 
vours to  assume  the  aspect  of  an  inanimate  substance, 
and  hitches  along  in  the  most  leisurely  manner  possi- 
ble. It  only  moves  one  leg  at  a  time,  and  having  set 
one  foot  forward,  it  pauses  a  little  before  it  brings  up 
the  contiguous  one,  proceeding  in  the  same  way  with 
its  other  legs.  It  is  no  less  carefully  cautious  in 
moving  its  antennae,  striking,  as  it  were,  first  with 
one,  and  then,  after  a  short  pause,  with  the  other. 
By  means  of  a  camel's  hair  pencil,  or  a  feather,  it  is 
easy  to  unmask  the  insect,  for,  when  touched,  it  usu- 
ally abandons  its  covering. 

*  Introd.  to  Ent.  iii,  1?6.  1   De  Geer,  ii,  674, 


CHAPTER  VII. 

Growth,  Moulting,  Strength,  Defence,  and  Hybernation  of  Larvae. 

FROM  the  facts  being  commonly  known,  we  are  not 
surprised,  that  an  ostrich,  nine  feet  high  and  150  Ibs 
weight,  should  be  produced  from  an  egg  about  the 
size  of  a  cocoa-nut,  or  that  {  a  grain  of  mustard-seed 
—  the  least  of  all  seeds  — when  it  is  grown,'  should 
become  <  a  tree  (Phytolacca  dioicaT),  so  that  the 
birds  of  the  air  come  and  lodge  in  the  branches 
thereof.'*  But  when  similar  facts  are  recorded  by 
naturalists  respecting  insects,  general  readers  are  apt 
to  wonder,  because  they  are  less  familiar  with  these 
details,  than  with  the  economy  of  trees  springing  from 
seeds  and  birds  being  produced  from  eggs.  When  we 
repeat,  after  Lyonnet,  that  the  caterpillar  of  the  goat- 
moth  (Cossus  ligniperda,  FABR.)  becomes  72,000 
times  heavier  than  when  newly  hatched,")"  we  do  not 
state  anything  more  striking  and  admirable  than  that 
an  embryo  of  small  dimensions  should  become  an  ele- 
phant, or  that  an  acorn  should  produce  a  lofty  and 
magnificent  oak.  The  facts  respecting  the  growth  of 
insects  have  an  adventitious  interest,  because,  in  con- 
sequence of  the  minuteness  of  the  objects  to  which 
they  relate,  they  are  less  familiar  to  popular  observa- 
tion. In  the  instance  of  the  silk-worm,  the  progress 
of  growth  has  been  accurately  ascertained  by  scientific 
cultivators.  It  appears  that  a  single  caterpillar, 
weighing  when  first  hatched  only  the  hundredth  part 
of  a  grain,  consumes  in  thirty  days  above  an  ounce  of 
leaves,  —  that  is  to  say,  it  devours  in  vegetable  sub- 


*  See  Irby  and  Mangle's  Travels,  letter  v. 
t  Traite  Anat.  de  la  Chenille,  p.  11, 


GROWTH    OF    SILK-WORMS.  167 

stance  about  60,000  times  its  primitive  weight.  In 
warmer  climates,  silk-worms  consume  a  rather  less 
quantity  of  leaves,  because  these  are  perhaps  more 
nutritive;  but,  in  that  case,  the  silk  produced  is  not 
so  delicate  and  fine.  The  following  statements  are 
the  result  of  experiments  made  by  Count  Dandolo:  — 

Progressive  increase  of  silk-worms  in  weight. 

GRAINS 

A  hundred  worms  just  hatched  weigh  about  1 

After  the  first  moulting  15 

After  the  second  moulting  94 

After  the  third  moulting  400 

After  the  fourth  moulting  1628 

On  attaining  their  greatest  size  and  weight  9500 

They  have,  therefore,  in  thirty  days  increased  9500 
times  their  primitive  weight. 

Progressive  increase  of  silk-worms  in  length. 

LINES. 

A  silk-worm  just  hatched  measures  about  1 

After  the  first  moulting  4 

After  the  second  moulting  6 

After  the  third  moulting  12 

After  the  fourth  moulting  20 

After  the  fifth  moulting  it  may  reach  40 

The  length  of  the  silk-worm,  therefore,  increases 
about  forty  times  in  twenty-eight  days.* 

.By  recalling  to  memory  the  comparisons  of  the 
eggs  of  insects  with  the  seeds  of  plants,  and  of  cater- 
pillars with  buds,  which  ought  to  be  taken  (if  we 
may  trust  Swammerdam)  literally  rather  than  poeti- 
cally >  we  shall  arrive  at  more  distinct  notions  of 
the  manner  in  which  the  growth  and  changes  of 
larvae  are  accomplished.  The  buds  of  plants  are 
composed  of  successive  leaves  closely  embosomed 
within  each  other's  foldings,  the  outer  one  being 
generally  hard  and  corneous,  from  the  exposure  of 
its  vessels  to  the  colds  of  winter,  while  the  inner 

*  Count  Dandolo  on  Silk-worms,  p.  326,  Eng.  Trans. 


168  INSECT    TRANSFORMATIONS. 

leaves,  being  thence  protected,  remain  soft  and  pulpy, 
But  as  soon  as  the  inner  leaves  receive  an  accession 
of  sap,  which  rises  from  the  roots  on  the  return  of 
spring,  their  vessels  swell  and  their  nervures  expand; 
while  the  outer  leaf,  from  its  vessels  being  shrunk  and 
partly  obliterated,  undergoes  little  change  besides 
being  pushed  out  and  sometimes  entirely  thrown  off 
by  the  growth  of  the  inner  leaves,  which  it  had  pre- 
viously enclosed.  It  may  be  remarked,  also,  that  this 
outer  envelope  of  a  bud  is  not  united  witb  the  inner 
leaves  by  any  interlacing  of  their  substance  or  of 
their  vessels,  though  in  some  cases  there  is  an  adhe- 
sive gluten  which  partly  binds  them  together;  but  this 
is  never  so  strong  as  to  prevent  the  expansion  of  the 
leaves.  On  comparing  one  of  the  bud  envelopes  thus 
thrown  off,  we  can  scarcely  persuade  ourselves  that 
so  small  a  covering  could  ever  have  contained  the 
large  spreading  leaves  which  have  burst  from  them. 

A  caterpillar  corresponds  in  several  circumstances 
with  the  leaf  bud.  The  outer  skin  encloses  a  suc- 
cession of  several  other  skins  each  becoming  more 
delicate,  soft,  and  indistinct  than  the  one  exterior  to 
it,  but  gradually,  like  the  expanding  leaves,  growing 
more  substantial  and  firm  as  it  receives  a  supply  of 
nutriment.  The  chief  mechanical  difference  be- 
tween the  leaves  folded  up  in  the  bud  and  the  suc- 
cessive caterpillars  enveloped  within  the  skin  of  one 
newly  hatched,  is  that  the  leaves  in  the  bud  receive 
all  their  nourishment  through  their  foot- stalks  from 
the  root  of  the  tree,  whereas  the  caterpillar  is  nour- 
ished from  within  by  the  food  digested  in  its  stomach. 
The  superfluous  nourishment,  usually  in  considerable 
quantity,  and  called  the  fat  of  the  caterpillar,  appears 
to  lie  between  the  successive  skins,  in  a  similar  way 
to  the  adhesive  gluten  in  the  leaf  bud.  But  as  the 
first  inner  skin  expands  and  increases  in  consistence. 


MOULTING  OF  CATERPILLARS.        169 

the  fat  which  lies  between  it  and  the  outer  skin 
seems  to  be  absorbed  into  the  bod  t  of  the  cater- 
pillar, and  of  course  swelling  it  out;  while  its  abstrac- 
tion from  the  interior  of  the  outer  skin  renders  this 
much  more  dry,  separates  it  from  the  inner  skin,  and 
disposes  it  to  harden  and  shrivel. 

The  absorption  of  the  fat  also  produces  the  re- 
markable consequence  of  gorging  all  the  channels  of 
nutrition,  so  that  there  is  no  longer  any  demand 
upon  the  stomach  for  fresh  supplies  of  food;  and 
hunger  (which  we  imagine  is  caused  either  by  the 
want  of  the  accustomed  pressure  of  food  on  the 
terminal  nerves  in  the  stomach,  or  of  the  irritation  of 
the  absorbents  when  they  are  left  empty)  is  no 
longer  felt.  The  caterpillar  accordingly  ceases  to 
eat,  and  having  no  incentive  to  action  remains  motion- 
less. The  outer  skin,  in  the  meanwhile,  being 
deprived  of  its  internal  moisture  by  the  absorption  of 
the  fat,  goes  on  to  harden  and  shrink,  while  all  the 
internal  organs  become  enlarged  by  the  nutritive  fat. 
The  expansion,  therefore,  of  the  body  of  the  cater- 
pillar on  the  one  hand,  and  the  shrinking  of  the  old 
skin  on  the  other,  produce  a  mutual  struggle,  which, 
from  the  continued  operation  of  the  causes,  must,  it 
is  obvious,  be  soon  brought  to  a  termination. 

The  skin,  from  losing  its  internal  moisture,  loses 
also  a  portion  of  its  colour,  and  becomes  obscure 
and  dull;  and  the  caterpillar,  from  being  girt  and 
squeezed  by  its  pressure,  begins  to  turn  and  twist 
itself  in  various  directions,  to  rid  itself  if  possible  of 
the  inconvenience.  By  continuing  these  movements, 
the  creature  succeeds  at  length  in  rending  the  old 
skin  at  its  weakest  part,  which  is  usually  on  the 
back,  just  behind  the  head;  and  in  a  few  minutes, 
using  its  body  as  a  wedge,  it  may  be  seen  issuing 
through  the  breach.*  The  old  skin  is  thus  abandoned 

*  Reaumur,  Mem.  i,  135. 
VOL.  vi.  15 


170  INSECT    TRANSFORMATIONS. 

like  a  worn  shirt;  and  the  caterpillar  appears  in  an 
entire  new  dress,  the  tints  of  which  are  fresher  and 
brighter,  and  the  colours  and  markings  often  con- 
siderably different  from  the  former.  The  insect, 
also,  in  consequence  of  the  quantity  of  fat  which  has 
gone  to  augment  its  several  parts,  becomes  all  at 
once  so  much  enlarged  in  size,  that  we  can  with  diffi- 
culty conceive  how  it  could  have  been  contained  in 
the  old  skin,  out  of  which  it  has  just  crept.  The 
cast  skin  is  frequently  so  very  perfect  that  it  might 
almost  be  supposed  to  be  the  caterpillar  itself,  particu- 
larly in  those  which  are  hairy,  as  this  contributes  to 
conceal  the  shrivelling. 

That  the  above  account  of  the  process  of  casting  the 
skin  is  correct,  appears  both  from  the  careful  dissections 
which  have  been  made  by  Swammerdam,  Lyonnet, 
and  Ramdohr,  and  also  from  the  diseases  incident 
to  caterpillars  from  deficiency  of  food  or  of  pure  air. 
It  is  a  circumstance  of  common  occurrence  to  those 
who  are  in  the  habit  of  breeding  insects,  that  when 
they  are  not  supplied  with  a  sufficient  quantity  of 
food,  their  bodies  do  not  increase  enough  in  thick- 
ness to  rupture  the  old  skin;  yet  this  becomes  in  due 
time  hard  and  shrivelled  from  the  absorption  of  the 
fat,  though  the  insect,  from  its  inability  to  break 
through,  remains  imprisoned.  It  might  be  sup- 
posed, that  if  plenty  of  food  were  at  this  moment 
supplied,  it  would  subsequently  acquire  sufficient  bulk 
and  strength  to  rupture  and  escape  from  the  old  skin; 
but  this  is  impossible,  as  we  have  repeatedly  found 
to  our  great  disappointment.  In  the  instance  of 
the  caterpillar  of  the  moth,  called  by  collectors  the 
glory  ©f  Kent  (Endromis  versicolora,  STEPHENS), 
which  we  found  on  a  lime-tree  at  Lee,  and  were 
anxious  to  rear,  fresh  food  was  neglected  to  be 
given  to  it  a  short  time  before  its  third  moult;  and 
from  that  time  it  refused  to  eat,  and  soon  died.  By 


MOULTING  OF  CATERPILLARS.        171 

minute  examination  we  found  that  it  was  impossible 
for  it  to  eat,  as  all  its  organs  were  in  a  state  of 
forward  preparation  for  throwing  off  their  exterior 
coat,  —  the  old  skin,  in  fact,  covering  them  as  a  glove 
does  the  hand,  ard  the  new  head  lying  distinctly 
farther  back  than  the  old.  Neither  the  old  man- 
dibles therefore,  which  were  become  dry  and  stiff, 
nor  the  new  ones,  which  were  encased  in  these, 
could  bite  the  leaves;  and  even  if  this  had  been 
accomplished,  the  entrance  to  the  gullet  was  ob- 
structed by  the  shrivelling  of  the  old  skin  there, 
and  deglutition  could  not  have  taken  place.  The 
poor  caterpillar  was  in  consequence  starved  to  death 
in  the  midst  of  abundance  of  food,  which  it  could 
neither  chew  nor  swallow.  Had  it  been  skilfully 
assisted  (as  it  was  not)  to  get  rid  of  the  encum- 
brance of  its  old  skin,  we  doubt  not  that  it  might 
ultimately  have  recovered.*  Reaumur  mentions  the 
very  singular  circumstance  of  a  caterpillar  of  the 
six-spot  burnet  moth  (Jlnthrocera  Filipendulce, 
STEPHENS)  having  actually,  before  its  last  moult,  bit 
off  portions  of  its  old  skin,  which  it.  first  raised  up 
and  afterwards  detached  and  tossed  away.  He  did 
not,  however,  ascertain  whether  this  was  an 
accidental  manoeuvre,  or  the  usual  process  of  this 
species  of  caterpillar  ;|  though  the  first,  we  think,  is 
the  more  probable. 

The  disorder  called  the  Reds  by  the  breeders  of 
silk-worms,  shows  itself  in  red-coloured  stains  and 
blotches  upon  the  skin;  while  the  caterpillars  seem 
cramped,  stupified,  and  suffocated,  their  rings  dry  up, 
and  they  look  exactly  like  mummies.  Count  Dando- 
lo  refers  this  and  most  other  diseases  of  silk- worms  to 
chemical  agency.  The  great  quantity  of  vegetable 
food  devoured  by  caterpillars  must  be  liable,  during 
hot  weather  to  fermentation,  if  it  be  not  digested 

*  J.  R.  t  Reaumur,  Mem.  ii,  75, 


172  INSECT    TRANSFORMATIONS. 

soon  after  it  is  swallowed,  —  a  process  which  often 
terminates  in  the  production  of  an  acid  ;  and  as 
acids  have  a  tendency  to  redden  vegetable  colours, 
the  red  hlotches  are  plausibly  ascribed  to  that 
cause.  This  conjecture,  which  originated  with 
Count  Dandolo,  has  been  proved  to  be  the  fact  by 
Professor  Brugnatelli;  who  made  the  very  unexpect- 
ed discovery  that  the  red  matter  contains  uric  acid 
combined  with  ammonia,  and  consequently  that  the 
disorder  is  similar  in  its  proximate  cause  to  what  is 
called  the  red  gravel  (Lilhia  renalis  £r  GOOD)  in 
man.  This  acid,  then,  from  its  excess  in  diseased 
caterpillars,  impedes  the  process  of  nutrition,  and 
prevents  the  animal  from  acquiring  sufficient  strength 
to  throw  off  the  old  skin  when  the  time  for  this  ar- 
rives. 

It  appears,  also,  from  the  experiments  of  Count 
Dandolo,  that  though  caterpillars  can  live  longer  in 
air  deprived  of  oxygen,  or  otherwise  contaminated, 
than  warm-blooded  animals,  yet  they  do  not  thrive, 
and  are  very  liable  to  diseases,  when  they  have  not 
access  to  fresh  air.  In  other  words,  the  food  which 
has  been  digested  cannot  without  oxygen  be  con- 
verted into  the  fluid  analogous  to  blood;  and  in  such 
cases,  as  we  have  repeatedly  witnessed,  instead  of 
being  appropriated  to  nourishment,  it  is  thrown  into 
the  intestines,  producing  diarrhosa,  or  scour,  as  it  is 
termed  by  the  cultivators  of  the  silk-worm.  In  this 
case  the  inner  skin  never  acquires  sufficient  consist- 
ence, nor  can  the  old  one  ever  become  dry  enough  to 
be  cast. 

One  of  the  most  singular  circumstances  respecting 
the  moult  of  caterpillars,  is  the  manner  in  which  the 
hairs  are  disposed  in  the  new  skin  before  moulting. 
These  are  not>  like  the  feet  and  other  organs,  sheath- 
ed in  the  hairs  of  the  old  skin,  but  smoothly  folded 
down  in  separate  tufts;  and  if  the  old  skin  be 


MOULTING    OF    CATERPILLARS. 


173 


removed  a  short"  time  before  it  would  be  naturally  cast, 
these  tufts  may  be  seen  in  a  moist  state  very  similar  to 
small  wetted  camePs-hair  pencils  lying  close  to  the  in- 


pillar  of  the  sycamore 
VOL.    VI. 


174  INSECT  TRANSFORMATIONS. 

ner  skin,  — those  on  the  fore  part  of  the  body  laid  to- 
wards the  head,  and  from  the  fourth  ring  backwards  in 
a  contrary  direction. 

Swarnmerdarn,  R  aumur,  and  other  naturalists,  re- 
peatedly tried  the  experiment  of  cutting  off  the  hair 
from  caterpillars  about  to  moult,  without  in  the  least 
affecting  the  hairs  on  the  new  skin;  bi>t  when  a  foot 
or  any  other  member  is  accidentally  multilated,  it  is 
also  wanting  in  the  moulted  caterpillar,  facts  which 
strongly  corroborate  the  details  we  have  given  above. 

It  is  a  still  more  singular  circumstance,  ascertained 
by  Svvarnmerdam,  De  Geer,  Lyonnet,  and  Bonnet, that 
caterpillars  and  grubs  not  only  cast  their  exte  nal  skins, 
but  also  that  which  lines  their  breathing-tubes  and  in- 
testines. '  Some  days,'  says  Bonnet,  (  before  the 
change,  the  caterpillar  voids  along  with  its  excrements 
the  membrane  which  invests  the  interior  of  its  stomach 
and  intestines.  I  have  also  remarked,  that  during  the 
moult,  packets  of  the  tracheal  vessels  may  be  seen 
attached  to  the  cast  skin,  and  thrown  off  along  with  it.' 
De  Geer  has  distinctly  seen  white  fibres  proceeding 
from  the  interior  spiracles  of  a  butterfly  remain  at- 
tached to  the  pupa-case.  He  conjectures  that  these 
fibres  consist  of  the  delicate  membrane  which  lines  the 
wind-pipes;  and  that  they  are  moulted  like  the  lining 
of  the  stomach  of  a  lobster,  or  of  a  caterpillar.  Ly- 
onnet, in  some  measure,  confirms  this  conjecture.* 

In  his  admirable  description  of  the  rhinoceros-beetle 
(Orycles  nasicornis^  Swammerdam  says  of  the  grub: 
£  Nothing  in  all  nature  is,  in  my  opinion,  a  more  won- 
derful sight,  than  the  change  of  skin  in  these  and  other 
the  like  grubs.  This  matter,  therefore,  deserves  the 
greatest  consideration,  and  is  worthy  to  be  called  a 
specimen  of  Nature's  miracles.  For  it  is  not  the  ex- 

*  Bonnet,  CEuvres,  vol.  viii,  pp.  303-311. 


MOULTING    OF    GRUBS. 


175 


ternal  skin  only  that  these  grubs  cast,  like  serpents; 
but  the  throat  and  a  part  of  the  stomach,  and  even  the 
inward  surface  of  the  great  gut,  change  their  skin  at 
the  same  time.  Yet  this  is  not  the  whole  of  these  won- 
ders; for  at  the  same  time  some  hundreds  of  breath- 
ing-pipes within  the  body  of  the  grub  cast  also  each  its 
delicate  and  tender  skin.  These  several  skins  are 
afterwards  collected  into  eighteen  thicker,  and,  as  it 
were,  compounded  ropes,  nine  on  each  side  of  the 
body,  which,  when  the  skin  is  cast,  slip  gently  and 
by  degrees  from  within  the  body  through  the  eighteen 
apertures  or  orifices  of  the  tubes  before  described, 
having  their  tops  or  ends  directed  upwards  towards  the 
head.  Two  other  branches,  also,  of  the  breathing 
pipes,  that  are  smaller  and  have  no  point  of  respira- 
tion, cast  a  skin  likewise.  If  any  one  separates  the 
cast  little  ropes,  or  congeries  of  breathing  pipes  with 
a  fine  needle,  he  will  very  distinctly  see  their  several 


Exuvia  and  pulmonary  vessels  of  the  rhinoceros  beetle  (Oryctcs  na$i- 
cornis).  A,  magnified  view  of  a  pulmonary  branch  and  vesicle;  «  ", 
pulmonary  branch,  composed  of  a  membranous  sheath  and  cartilagi- 
nous lings 5  6.  vesicle.  B,  larva;  c  c,  nine  reddish  breathing  holes. 
C,  exuvia,  or  cast  skin  of  the  larva,  A  d  d  d,  skins  of  the  pulmonary 
tubes. 


176  INSECT   TRANSFORMATIONS. 

branches  and  ramifications,  and  also  their  ringed  struc- 
ture.'* 

The  caterpillars  of  moths  and  butterflies  generally 
cast  their  skins  five  times;  but  some  cast  them  seven 
and  even  ten  times,  as  in  the  case,  according  to 
Cuvier,  of  the  great  tiger-moth  (Jlrciia  Caja,  STE- 
PHENS). By  the  breeders  of  silk-worms  this  natural 
process  is  ranked  among  their  maladies;  and  not  alto- 
gether without  reason,  as  it  frequently  proves  fatal, 
from  causes  to  which  we  have  already  alluded.  For 
several  hours,  often  for  a  whole  day,  after  casting  the 
skin,  the  caterpillar  continues  sluggish  and  moves  little; 
and  as  the  vessels  are  still  replete  with  the  fat  previ- 
ously absorbed,  there  is  no  stimulus  for  it  to  eat.  But 
as  soon  as  this  supply  is  exhausted,  it  commences 
again  to  eat  voraciously,  in  order  to  supply  another 
store  of  fat  for  its  succeeding  moult. 

The  moulting  of  caterpillars,  it  may  be  remarked, 
bears  but  a  slight  resemblance  to  the  casting  of  the 
feathers  in  birds,  and  the  hair  in  quadrupeds.  Birds 
generally  cast  their  feathers  once,  and  many  twice, 
a-year,  namely  in  autumn  and  in  spring;!  and  quad- 
rupeds in  a  similar  way  cast  their  hair.  But  in 
both  these  cases  the  process  is  gradual,  and  resem- 
bles that  of  shedding  the  milk-teeth  when  the  jaw 
enlarges.  All  of  these  changes,  however,  produce 
considerable  derangements  in  the  animals;  and  they 
are  seldom  accomplished  without  disordering  health, 
and  sometimes  endangering  life.  The  great  differ- 
ence between  the  changes  in  insects  and  the  other 
classes  of  animals  evidently  arises  from  the  differ- 
ence of  their  internal  structure.  It  must  be  obvi- 
ous to  all,  for  example,  that  the  human  body  wears. 
As  old  age  advances  the  bones  waste  away  and 
become  smaller,  the  muscles  and  skin  shrink  and 

*  Swammerdam,  Bib.  Nat.,  vol.  i,  p.  135. 
t  Temminck,  Manuel  d'Qrnithol.  Intr. 


MOULTING    OF    GRUBS.  177 

grow  dry  and  shrivelled,  and  the  stature  grows  shorter 
and  more  diminutive.  Even  in  youth  similar  changes 
are  in  progress,  a  system  of  absorbent  vessels  being 
pro\7ided  tor  removing  worn  materials  from  all  parts 
of  the  body,  and  carrying  at  least  one  portion  of  these 
along  with  the  blood  into  the  lungs,  whence  it  goes 
off  in  minute  particles  with  the  breath.  JNo  similar 
process  of  removing  worn  materials  has,  so  far  as  we 
know,  been  discovered  in  caterpillars;  and  it  is,  in- 
deed, improbable,  as  the  successive  changes  of  the 
skin  accomplish  all  that  is  wanted  in  this  respect.  That 
the  worn  materials,  however,  of  the  cast  skins  are 
not  altogether  useless,  appears  from  the  singular 
circumstance  of  the  new-clothed  caterpillar  often 
devouring  them,  as  that  of  the  hawthorn-butterfly 
(Pieris  Cratcegi,  STEPHENS)  does  the  shell  of  the 
egg  it  has  just  been  hatched  from.*  It  may  be 
remarked,  that  it  is  chiefly  the  larger  caterpillars  of 
the  puss  and  some  of  the  hawk-moths  which  have 
been  observed  to  eat  their  skins;  none  of  the  spi- 
nous  or  hairy  ones  seem  to  relish  this  strange  sort  of 
food.  In  the  case  of  the  warty -eft  (Tiifon  palustris, 
FLEM.),  which  frequently  casts  its  outer  skin,  we  have 
observed  that  it  is  frequently  eaten  by  the  animal 
itselft 

The  grubs  of  some  two  winged  flies  (Muscidce)y 
and  of  wasps,  bees,  ants,  and  ichneumon  flies,  do 
not  change  their  skins  like  the  larvas  we  have  just 
been  considering;  but  spiders  and  other  allied  tribes 
(Jlrachnidce) ,  though  they  exhibit  no  other  appear- 
ance of  larvas,  moult  frequently  during  their  growth. 
Goldsmith,  amongst  other  curious  mis-statements 
respecting  a  house-spider  which  he  himself  observed, 
asserts  that  it c  lived  three  years,  every  year  it  changed 
its  skin,  and  got  a  new  set  of  legs:  1  have  sometimes 
plucked  off  a  limb,  which  grew  again  in  two  or  three 

*  Bonnet,  CEuvres,  vol.  ii>  p.  18.  t  J  R. 


178  INSECT    TRANSFORMATIONS. 

days.'  The  fact  is,  that  few  spiders  live  one  year, 
much  less  three;  and  all  their  changes  of  skin  are 
gone  through  in  a  few  months,  and  their  acquiring 
new  legs  for  mutilated  ones  takes  some  weeks.  It  is 
probable,  indeed,  that  Goldsmith  never  thought  of  as- 
certaining the  identity  of  this  spider;  if  the  whole  story 
be  not  a  mere  fancy,  like  his  assertion  that  spiders, 
'  when  they  walk  upon  such  bodies  as  are  perfectly 
smooth,  as  looking-glass  or  polished  marble,  squeeze  a 
little  sponge  which  grows  near  the  extremity  of  their 
claws,  and  thus  diffusing  a  glutinous  substance,  adhere 
to  the  surface  till  they  make  .a  second  step.'*  Nei- 
ther spiders  nor  any  insects  with  which  we  are  ac- 
quainted can  thus  produce  gum  from  their  feet  to  aid 
them  in  walking  upon  glass,  though  the  house-fly  can 


Goat  moth  caterpillar  (Cossus  ligniperda)  escaping  from  a 
drinking  glass,  by  spinning  a  ladder  of  silken  ropes. 

*  Animated  Nature,  pt   vi,  ch.  iii.     See  also  Insect  Archi 
tecture,  pp.  367-8. 


MUSCULAR    STRENGTH    OF    INSECTS.  179 

walk  thus  by  causing  a  vacuum  between  its  feet  and 
the  glass,  as  we  shall  subsequently  describe  at  length. 
But  the  spider  and  all  caterpillars  can  only  climb  in 
such  cases  by  constructing  a  ladder  of  ropes,  as  is  re- 
presented by  Rb'sel  in  the  instance  of  the  goat  moth 
caterpillar. 

One  of  these  caterpillars,  which  we  possessed,* 
made  its  escape  in  a  manner  much  more  unexpected, 
if  not  so  ingenious,  by  means  of  its  great  muscular 
power,  in  which,  it  is  not  a  little  singular,  that 
insects,  as  Baron  Haller  remarks,  appear  to  excel  in 
proportion  to  their  diminutiveness.  Of  this  we  have 
a  remarkable  example  in  the  common  flea,  which 
can  draw  seventy  or  eighty  times  its  own  weight. f 
The  muscular  strength  of  this  agile  creature  enables 
it  not  only  to  resist  the  ordinary  pressure  of  the 
fingers  in  our  endeavours  to  crush  it,  but  to  take 
leaps  to  the  distance  of  two  hundred  times  its  own 
length;  which  will  appear  more  surprising  when  we 
consider  that  a  man,  to  equal  the  agility  of  a  flea, 
should  be  able  to  leap  between  three  and  four  hun- 
dred yards.  The  flea,  however,  is  excelled  in  leap- 
ing by  the  cuckoo-spit  frog-hopper  (  Tettigonia  spu- 
maria,  OLIVIER),  which  will  sometimes  leap  two  or 
three  yards,  that  is,  more  than  250  times  its  own 
length  ;J  as  if  (to  continue  the  comparison)  a  man 
of  ordinary  stature  should  vault  through  the  air 
to  the  distance  of  a  quarter  of  a  mile.  The  minute 
observation  by  which  such  unexpected  facts  are  dis- 
covered has  in  all  ages  been  a  fertile  source  of  ridi- 
cule for  the  wits,  from  the  time  when  Aristophanes 
in  his  Clouds  introduced  Socrates  measuring  the 
leap  of  a  flea,§  up  to  Peter  Pindar's  lampoon  on 

*  See  Insect  Architecture,  p.  189. 
t  Haller,  Physiol.,  vol.  ix,  p.  2. 
J  De  Geer,  Mem.,  vol.  hi,  p.  178. 
$  Aristophanes,  Nfp«x*/,  *,  £. 


180  INSECT    TRANSFORMATIONS. 

Sir  Joseph  Banks  and  the  emperor-butterfly.  To 
all  such  flippant  wit  we  have  merely  to  retort  the 
question  of  the  Abbe  de  la  Pluche,  '  if  the  Deity 
thought  insects  worthy  of  his  divine  skill  in  form- 
ing them,  ought  we  to  consider  them  beneath  our 
notice?'* 

MoufFet,  in  his  Theatre  of  Insects,!  mentions  that 
an  English  mechanic,  named  Mark,  to  show  his  skill, 
constructed  a  chain  of  gold  as  long  as  his  finger, 
which,  together  with  a  lock  and  key,  were  dragged 
along  by  a  flea;  and  he  had  heard  of  another  flea 
which  could  draw  a  golden  chariot,  to  which  it  was 
harnessed.  Bingley  tells  us  that  Mr  Boverich,  a 
watchmaker  in  the  Strand,  exhibited  some  years  ago 
a  little  ivory  chaise  with  four  wheels,  and  all  its 
proper  apparatus,  and  the  figure  of  a  man  silting  on 
the  box,  all  of  which  were  drawn  by  a  single  flea. 
The  same  mechanic  afterwards  constructed  a  minute 
landau,  which  opened  and  shut  by  springs,  with 
the  figures  of  six  horses  harnessed  to  it,  and  of  a 
coachman  on  the  box,  a  dog  between  his  legs,  four 
persons  inside,  two  footmen  behind  it,  and  a  postilion 
riding  on  one  of  the  fore  horses,  which  were  all 
easily  dragged  along  by  a  single  flea.J  Gold- 
smith remarks  upon  these  displays  of  pulician 
strength,  that  the  feats  of  Samson  would  not,  to  a 
community  of  fleas,  appear  to  be  at  all  miraculous. § 
Latrellle  tells  us  a  no  less  marvellous  story  of 
another  flea,  which  dragged  a  silver  cannon  twenty- 
four  times  its  own  weight,  mounted  on  wheels,  and 
did  not  manifest  any  alarm  when  this  was  charged 
with  gunpowder  and  fired  oflf.||  Professor  Bradley, 
of  Cambridge,  also  mentions  a  remarkable  instance 
of  insect  strength  in  a  stag-beetle  (Lucanus  Cervus) 

*  Spectacle  de  la  Nature,  i,  3.  +  Page  275. 

t  Animal  Biography,  iii,  468.     (Animated  Nature,  iv,  178. 
|i  Nouv.  Diet.  d'Hist.  Nat.  xxviii,  249. 


MUSCULAR    STRENGTH    OF    INSECTS.  181 

which  he  saw  carrying  a  wand  a  foot  and  a  half  long, 
and  half  an  inch  thick,  and  even  flying  with  it  to  the 
distance  of  several  yards. * 

It  has  been  remarked,  with  reference  to  these  facts 
of  comparative  size  and  strength,  that  a  cock-chafer 
is  six  times  stronger  than  a  horse  ;  and  Linnaeus 
observes,  that  if  an  elephant  were  as  strong  in 
proportion  as  a  stag-beetle,  it  would  be  able  to 
tear  up  rocks  and  level  mountains.  The  muscular 
power  of  fish,  however,  seems  to  bear  a  near  compa- 
rison with  that  of  insects.  c  I  have  seen,'  says  Sir 
Gilbert  Blane,  c  the  sword  of  a  sword-fish  sticking 
in  a  plank  which  it  had  penetrated  from  side  to  side  ; 
and  when  it  is  considered  that  the  animal  was  then 
moving  through  a  medium  even  a  thousand  times 
more  dense  than  that  through  which  a  bird  cleaves 
its  course  at  different  heights  of  the  atmosphere,  and 
that  this  was  performed  in  the  same  direction  with 
the  ship,  what  a  conception  do  we  form  of  this  dis- 
play of  muscular  strength. 'y  It  should,  however, 
be  observed,  that  the  muscular  power  of  the  sword- 
fish  is  principally  shown  in  the  rate  of  swimming,  by 
which  the  animal  overtakes  the  ships,  and  thus  ac- 
quires the  momentum  which  determines  the  force 
of  the  blow.  We  may  understand  the  proximate 
cause  of  the  strength  of  insects,  when  we  look 
at  the  prodigious  number  of  their  muscles  —  the 
fleshy  belts  or  ribbons  by  whose  means  all  animal 
motions  are  performed.  The  number  of  these  in- 
struments of  motion  in  the  human  body  is  reckoned 
about  529  ;  but  in  the  caterpillar  of  the  goat-moth, 
Lyonnet  counted  more  than  seven  times  as  many  : 
in  the  head,  228  ;  in  the  body,  1647  ;  and  around 
the  intestines,  2186  ;  which,  after  deducting  20, 

*  Bradley,  Phil.  Account,  p    184. 
t  Gilbert  Blane,  Select  Diss.  p.  281. 
VOL.    VI.  16 


182 


INSECT    TRANSFORMATIONS. 


Magnified  view  of  the  principal  dorsal  muscles  of  the  upper  half  of  tho 
Cossus,  from  Lyonnet. 


MUSCULAR    STRENGTH    OF    INSECTS.  183 

common   to  the   head   and   gullet,   gives   a  total  of 
4061.* 

'  Any  lady,'  says  Kirby  and  Spence,  c  fond  of 
going  to  be  tempted  with  an  exhibition  of  fine  lace, 
would  experience  an  unexpected  gratification  could 
she  be  brought  to  examine  the  muscles  of  a  caterpillar 
under  the  microscope  :  with  wonder  and  delight  she 
would  survey  the  innumerable  muscular  threads  that 
in  various  directions  envelope  the  gullet,  stomach, 
and  lower  intestines  of  one  of  those  little  animals;  — 
some  running  longitudinally,  others  transversely, 
others  crossing  each  other  obliquely,  so  as  to  form 
a  pattern  of  rhomboids  or  squares ;  others,  again, 
surrounding  the  intestine  like  so-  many  rings,  and 
almost  all  exhibiting  the  appearance  of  being  woven, 
and  resembling  fine  lace,  —  one  pattern  ornamenting 
one  organ ;  another,  a  second  ;  and  another,  a 

third.'! 

We  put  the  caterpillar  of  the  goat-moth,  to  which 
we  have  before  alluded,  under  a  bellglass,  which  weigh- 
ed nearly  half  a  pound,  and  of  course  more  than  ten 
times  the  weight  of  the  insect  ;  yet  it  raised  it  up 
with  the  utmost  ease.  We  then  placed  over  the  glass 
the  largest  book  which  we  had  at  hand  —  c  London's 
Encyclopedia  of  Gardening,'  consisting  of  about  1500 
pages  of  strong  paper,  and  weighing  four  pounds;  but 
this  did  not  succeed  in  preventing  the  escape  of  the 
animal,  which  raised  the  glass,  though  loaded  with  the 
book,  nearly  a  hundred  times  its  own  weight,  and  made 
good  its  exit.  J  The  multiplicity  of  its  muscles  above 
enumerated,  two  hundred  and  thirty-six  of  which  are 
situated  in  the  legs  alone,  will  enable  us  to  understand 
how  this  extraordinary  fete  was  performed.  Even  this 
power  of  muscle,  however,  would  doubtless  have  been 

*  Lyonnet,  Traite  Anat.  de  la  Chenille,  pp.  188,  584. 
t  Intr.  iv,  186.  $  J.  R. 


184  INSECT    TRANSFORMATIONS. 

unavailing  in  raising  the  loaded  glass,  except  in  con- 
nexion with  two  favourable  circumstances  under  which 
the  experiment  was  performed,  and  which  are  neces- 
sary to  be  borne  in  mind  to  render  the  operation  per- 
fectly credible  :  —  1st,  that  the  wedge-like  form  of  the 
caterpillar- s  head,  in  connexion  with  the  peculiar  shape 
of  the  glass,  enable  it  to  lift  it  ;  —  and  2d,  that,  one 
side  of  the  glass  resting  on  the  table,  the  insect  only 
bore  half  the  weight  of  the  glass  and  book. 


Caterpillar  of  Cossus  escaping  from  under  a  loaded  glass. 

A  peculiar  toughness  of  external  covering  some- 
times supplies  the  place  of  this  muscular  power  in 
caterpillars.  A  singular  instance  occurs  in  the 
history  of  a  common  downy  two- winged  fly,  with 
gray  shoulders  and  a  brown  abdomen,  (Eristalis 
tenaXy  FABE,.).  The  grub,  which  is  rat-tailed,  lives 
in  muddy  pools,  with  the  water  of  which  it  has  some- 
times been  taken  up  by  paper-makers,  and,  though 
subjected  to  the  immense  pressure  of  their  ma- 


MUSCULAR    STRENGTH    OF    INSECTS.  185 

chinery,  it  has  survived  in  a  miraculous  manner. 
Such  is  the  account  originally  given  by  Linnaeus.* 
A  recent  compiler,  mistaking  Kirby  and  Spence's 
very  apt  comparison  of  this  grub  to  a  London  porter 
nicknamed  Leather-coat-Jack,  from  his  being  able  to 
suffer  carriages  to  drive  over  him  without  receiving 
any  injury,  forthwith  fancies  the  porter  to  be  '  another 
insect,  called  leather- coat-jack,'  which  ( will  bear 
heavy  carriage  wheels  to  pass  over  it  with  impunity.' 
Since  the  grub  in  question  is  rather  soft,  it  must  be 
the  tough  texture  of  the  skin  which  preserves  it,  as 
in  the  similar  instance  of  the  caterpillar  (figured  at 
page  125)  of  the  privet  hawk-moth  (Sphinx  Ligustri), 
which  Bonnet  squeezed  under  water  till  it  was  as  flat 
and  empty  as  the  finger  of  a  glove,  yet  within  an  hour 
it  became  plump  and  lively  as  if  nothing  had  happen- 
ed.! 

The  instances,  however,  which  we  have  just  re- 
corded are  peculiar  rather  than  general,  for  caterpillars 
are  for  the  most  part  very  easily  bruised  and  other- 
wise injured.  Those  which  are  large  and  heavy, 
therefore,  such  as  the  caterpillars  of  the  hawk-moths 
(Sphingidai),  have  the  power  of  attaching  themselves 
very  firmly  to  the  spots  where  they  feed  and  rest  by 
means  of  the  numerous  hooks  of  their  pro-legs,J  so 
that  it  is  almost  impossible  to  detach  them  from  the 
branch  to  which  they  are  clinging;  and  hence  col- 
lectors always  cut  the  branch  itself.  All  of  them 
have  the  means  of  breaking  their  fall  by  spinning  a 
cable  of  silk,  which  they  uniformly  do  when  acciden- 
tally forced  to  quit  their  situation.  Their  method  of 
climbing  up  this  cable  again  is  worthy  of  observation, 
for  it  differs  considerably  from  the  manoeuvre  of  spi- 
ders, under  the  same  circumstances;  as  must  be  ob- 

*  Fauna  Suecica,  1799. 

t  lionnet,  (Euvres,  vol.  ii,  p.  124. 

$  See  Insect  Architecture,  p.  307,  right-hand  figure. 

VOL.    VI.  16* 


186 


INSECT    TRANSFORMATIONS. 


vious  when  we  consider  that  the  spinneret  of  the  spi- 
der is  placed  near  its  tail,  while  that  of  the  caterpillar 
is  in  its  mouth.  The  spider  accordingly  drops  head 
downwards,*  but  when  it  wishes  to  remount  the  line, 
it  turns  round,  and  raising  its  head,  it  stretches  its  long 
triple-clawed  legs|  up  the  line,  which  it  bundles  up 
while  it  ascends.  The  caterpillar  on  the  other  hand, 
having  very  short  legs,  with  only  one  smooth  clawj 
would  make  but  slow  progress  in  this  manner,  which 
it  does  not  attempt;  but  bending  its  head  downwards 
till  it  can  grasp  the  cord  with  its  hinder  pair  of  feet, 


Methods  used  by  spiders  and  caterpillars  for  ascending  their 
threads.  The  caterpillars  are  those  of  ths  emperor-moth  (Satur- 
nia  Pavonia). 

•  Insect  Archil.,  page  336.  f  Ibid,  p.  367. 

*  Ibid,  p.  307,  left-hand  figure. 


MEANS  OF  DEFENCE  OF  CATERPILLARS. 


187 


and  then  raising  its  head  to  the  perpendicular  position 
again,  it  thus  effects  one  step.,  and  proceeds  in  the 
same  manner  till  it  reaches  the  top. 

Other  caterpillars,  when  they  are  disturbed,  employ 
a  different  method  of  breaking  their  fall  without 
spinning  a  thread,  taking  advantage,  for  this  purpose, 
of  the  long  hairs  which  cover  their  body.  Those 
who  have  seen  a  hedge-hog  (Erinaceus  Europceus), 
when  attacked  by  a  dog,  roll  itself  up  into  a  prickly 
ball,  will  readily  conceive  the  manoeuvre  of  the  cater- 
pillars to  which  we  allude,  it  being  precisely  similar. 


a,  Caterpillar  of  the  tiger-moth  (Arctia  Caja).  6,  the  same 
rolled  up  for  defence,  c,  grub  of  the-  museum-beetle.  <L  the 
same  magnified.  C)  tail  of  H;e  same,  magnified.  /,  $-,  its  hairs 


188  INSECT    TRANSFORMATIONS. 

Should  one  of  those  hairy  caterpillars,  when  feeding 
near  the  top  of  a  plant,  be  disturbed  or  alarmed,  it 
instantly  coils  itself  up  into  a  ball  and  drops  among 
the  grass.  Here  it  is  not  only  difficult  to  discover, 
but  equally  so  to  lay  hold  of  it;  for  the  pliancy  and 
smoothness  of  the  hair  causes  it  to  slip  through  the 
fingers  as  readily  almost  as  quicksilver.  The  grub 
of  the  museum  beetle  (Jlnthrenus  Museorum,  FABR.), 
the  pest  of  our  cabinets,  affords  another  example  of 
the  same  circumstance,  being  covered  with  tufts  of 
diverging  hairs  which  cause  it  to  glide  through  the 
fingers  as  if  they  had  been  oiled.  The  six  long  tufts 
at  the  tail,  which  it  can  erect  at  pleasure,  are  com- 
posed of  hairs,  which  rise  from  a  bulb  of  the  form  of 
a  halberd,  and  are  curiously  jointed  with  cones  through 
their  whole  extent.  The  bead  wood-louse  (Armadil- 
lo vulgaris,  CUVIER),  though  not  furnished  with 
hairs,  rolls  itself  up  into  a  round  ball,  trusting  to  the 
fine  polish  of  its  back  for  escape,  and  to  its  hardness 
for  defence.  c  One  of  our  maid-servants,'  says 
Swammerdam,  '  once  found  a  number  of  these  wood- 
lice  in  the  garden  contracted  into  round  balls,  and 
thinking  she  had  found  a  kind  of  coral  beads  she  be- 
gan to  put  them  one  after  another  on  a  thread;  it  soon 
happened  that  the  little  creatures,  being  obliged  to 
throw  off  the  mask,  resumed  their  motions:  on  seeing 
which,  she  was  so  greatly  astonished,  that  she  flung 
down  both  them  and  the  thread  in  great  haste,  crying 
out,  and  running  away.'* 

The  hairs  with  which  the  caterpillars  of  some  of 
our  finest  native  butterflies  are  furnished,  are  some- 
what of  the  nature  of  bristles  or  thorns,  being  hard, 
inflexible,  and  sharply  pointed.  This  is  the  case  with 
the  caterpillars  of  all  the  fan-winged  butterflies 
(Vanessce).  We  have  alluded  to  that  of  the  pea* 

*  Swammerdam,  pt  i,  p.  174. 


MEANS  OF  DEFENCE  OF  CATERPILLARS.   189 

cock's  eye,  which  must  be  conspicuous  to  birds  from 
its  dark  black  colour,  prettily  dotted  with  white,  aided 
besides  by  the  gregarious  habit  of  feeding  in  a 
colony  of  several  dozens  together;  but  if  a  thrush  or 
a  sparrow  pounces  upon  one  of  them,  the  formidable 
spines  must  present  an  obstacle  somewhat  unex- 
pected, perhaps,  to  the  making  of  a  comfortable 
meal.  The  ass,  indeed,  seems  to  relish  the  piquant 
stimulus  of  the  thorns  or  thistles,  and  sheep,  goats, 
and  deer  will  browse  on  the  still  sharper  leaves  of 
holly  ;*  but  we  think  none  of  our  soft-billed  birds 
would  venture  on  a  thorny  caterpillar.  Madame 
Merian  says  'that  the  spines  of  the  caterpillar  of 
Urania  Leilus  are  as  hard  as  iron  wire.'t  Abbot 
tells  us  that  many  American  caterpillars  sting  like  a 


Thorny  hairs  of  caterpillars.    a  a  a,  spiny  caterpillar,  from 
Madame  Merian.    6  6,  Vanessa  lo.    c,  spines  magnified. 

*  Withering,  Pot.   Arrangement.    Note  on  Ilex  aquifolium. 
t  Merian,  Insect.  Surinam,  xxix. 


I- 


190  INSECT     TRANSFORMATIONS. 

nettle,  and  blister  the  skin  when  touched;  which  is 
also  partly  exemplified  in  that  of  our  own  gipsey  moth 
(Hypogymna  dispar),  the  slender  hairs  of  which 
irritate  and  inflame  the  skin.  The  spines,  in  some  of 
the  caterpillars  alluded  to,  are  like  smooth  thorns  or 
prickles;  but  on  others,  they  are  beset,  or  feathered 
with  shorter  spines. 

It  is  probably  for  some  purpose  of  defence  or  con- 
cealment that  the  larvae  of  several  insects  form  a  sin- 
gular covering  for  themselves  of  their  own  excrements, 
which  they  pile  up  for  that  purpose  upon  their  backs. 
This  material,  as  Kirby  has  observed,  is  not  always  so 
offensive  as  might  be  supposed,  being  in  some  in- 
stances (  Cassida  maculata  et  Lnalidium  Leayanutn) 
formed  into  fine  branching  filaments,  like  lichens  or 
dried  fucus.*  Others,  however,  which  Reaumur 
aptly  terms  Hottentots,  do  not  appear  quite  so  cleanly. 
One  of  these,  rather  uncommon,  was  observed, 
many  years  ago,  by  Vallisnieri,  which  he  calls  the 
cantharidis  of  the  lily  (Crioceris  merdigera,  LEACH), 
and  may  be  found  in  May  on  Solomon's-seal,  and 
other  liliaceous  plants,  which  it  devours  and  renders 
unsightly.  Under  its  singular  canopy,  it  has  no 
resemblance  to  an  insect,  but  looks  like  an  oblong 
ball  of  chewed  grass  stuck  on  the  lily.  The  beetle 
which  is  produced  from  the  grub  is  of  a  fine  brownish 
scarlet,  and  elegantly  sculptured  with  minute  dots. 
Another  species,  more  abundant,  similar  in  man- 
ners, and  less  than  half  the  size  of  the  preceding 
(C.  cyanella,  PANZER),  is  of  a  fine  blue  colour,  with 
similar  dottings.  The  grub  of  the  green  tortoise- 
beetle  (Cassida  equestris,  FABR.),  usually  found  on 
burdocks,  is  furnished  with  a  more  ingenious  me- 
chanism for  this  purpose,  consisting  of  a  fork  in  its 
tail,  which  it  can  depress  or  elevate,  so  as  to  carry  its 
strange  canopy  higher  or  lower,  at  pleasure.  Like 

*  Linu.  Trans,  iii,  10. 


MEANS  OF  DEFENCE  OF  CATERPILLARS.   19! 

the  two  preceding  insects,  this  grab  is  also  most  unex- 
pectedly transformed  into  a  very  pretty  green  beetle, 
of  the  form  of  a  tortoise,  the  wing-cases  of  which 
project  all  round  as  a  covering  for  the  legs. 


A  C 

A,  Cassida  equestris.    B,  its  grub  magnified  to  show  its  anal 
forks.    C,  the  same  with  its  canopy  of  excrements. 

The  larva  of  the  golden-eyed  fly  ( Chrysopa  perla, 
LEACH),  whose  very  singular  eggs  we  formerly  men- 
tioned, covers  itself  with  the  fragments  of  the  aphides 
which  it  has  devoured,  —  a  moving  sepulchre  of  dry 
bones.* 

A  very  familiar  instance  of  this  mode  of  defence 
occurs  in  the  larva  of  the  cuckoo-spit  frog-hopper 
(  Tettigonia spumaria,  OLIVIER),  so  frequently  seen 
in  summer  on  willows,  rose-trees,  lychnis,  grass,  and 
other  plants.  This  creature  is  of  an  exceedingly  soft 
structure;  and  it  is  probably,  therefore,  as  a  protection 
from  the  sun,  that  it  throws  up  all  around  it  the  little 
tuft  of  white  froth,  called,  from  a  popular  mistake, 
cuckoo-spit.  The  perfect  insect  is  covered  with  hard 
wing-cases,  of  a  brown  colour,  with  a  white  spot  and 
pale  double  band. 

It  would  appear  that  the  hair,  which  we  have  de- 
scribed above  as  covering  the  bodies  of  some  cater- 
pillars, is  partly  intended  by  nature  to  defend  them 
from  cold  during  the  winter.  The  truth  of  this 
*  Reaumur,  iii,  380,  &c. 


192  INSECT    TRANSFORMATIONS. 


a,  The  spit  frog-hopper  (Tettigonia  spumariu)  flying.    6,  froth 
covering  the  grub  of  the  same. 

amounts  almost  to  demonstration,  from  a  circumstance 
discovered  respecting  ants  by  the  younger  Huber- 
<  The  larvae  of  some  ants,'  says  he,  '  pass  the 
winter  heaped  up  in  the  lowermost  floor  of  their 
dwelling.  1  have  found,  at  this  period,  very  small 
larvae  in  the  nests  inhabited  by  the  yellow  ant  (For- 
mica flava)j  the  field  ant  (F.  c&spitwnt) ,  and  some 
other  species.  Those  that  are  to  pass  the  winter  in 
this  state  are  covered  with  hair,  which  is  not  the  case 
in  summer;  affording  another  proof  of  that  Provi- 
dence at  which  naturalists  are  struck  at  every  step.'* 
The  same  growth  of  a  warmer  clothing  for  the 
winter  is  well  known  to  occur  among  quadrupeds, 
particularly  those  which  inhabit  the  higher  northern 
latitudes,  f 

Upon  the  same  principle,  a  number  of  the  cater- 
pillars whick  are  hatched  late  in  autumn,  and  are 
destined  to  live  over  winter,  are  provided  with  a 
warm  clothing  of  hair  or  down  This  is  the  case 
even  with  most  of  those  which  construct  for  them- 

*  M.  P.  Huber  on  Ants,  p.  82. 
t  See  Menageries,  vol.  i,  p.  50. 


MEANS  AND  DEFENCE  OF  CATERPILLARS.   193 

selves  a  snug  nest  of  silk,  such  as  the  caterpillars  of 
the  brown-tail  moth  (Porthesia  auriflua),  and  those 
of  the  mallow  butterfly  (Hesperia  malvce).  But  there 
are  others  which  are  provided  with  no  extraneous 
covering,  farther  than  the  occasional  shelter  they  may 
obtain  by  crawling  under  withered  leaves,  the  copings 
of  walls,  or  the  bend  of  a  branch.  Among  these 
some  are  thickly  covered  with  hair,  of  which  we  have 
an  instance  in  the  caterpillar  of  the  great  tiger  moth 
(Jlrctia  cajay  STEPHENS),  whose  mode  of  rolling  it- 
self up  into  a  ball  we  have  already  described;  but  a 
more  remarkable  example  occurs  in  the  caterpillar  of 
the  drinker  moth  (Odonestis  potatoria,  GERMAR.), 
whose  very  feet  are  covered  with  fine  shaggy  dow\ 
It  is  this,  no  doubt,  which  preserves  it  from  becoming 
torpid  during  winter,;  and  as  it  feeds  on  grass,  it  can 
always  procure  food  during  the  severest  weather. 
When  a  fine  sunny  day  chances  to  break  in  upon  the 
gloom  of  winter,  this  pretty  insect  may  be  often  seen 
stretched  at  its  full  length  on  a  low  twig,  or  the  with- 
ered stem  of  a  nettle,  basking  in  the  sunshine  with 
apparent  delight.  We  kept  one  of  them  in  our  study 
during  the  winter  of  1827-8;  and  it  continued  to  feed 
sparingly  till  February,  when,  owing  to  neglect,  it  un- 
fortunately died. 

There  are  several  other  caterpillars,  however, 
which  live  during  the  winter,  in  a  no  less  exposed 
manner,  without  being  provided  with  any  covering  of 
hair;  though  some  of  these,  we  may  remark,  do  not 
continue  to  feed,  but  become  wholly  or  partially  tor- 
pid, such  as  the  caterpillar  of  the  magpie  moth 
(Jlbraxas  grossulariata).  Of  this  species  we  have 
observed  numbers,  about  as  thick  as  a  crow-quill,  re- 
maining in  the  same  position  for  weeks  together,  and 
never  moving,  except  when  some  very  considerable 
change  of  temperature,  either  colder  or  hotter,  took 
place.  They  do  not  seem  to  select  the  warmest  places 

*  J.  R. 

VOL.    VI.  17 


194  INSECT    TRANSFORMATIONS. 

within  their  choice,  being  usually  found  on  an  expos- 
ed currant  branch,  or  under  the  upper  cross-bar  of  a 
paling.  We  observed  one,  during  several  months  of 
the  winter  of  1828-9,  stationary  under  the  lintel  of  a 
door,  where  a  continual  current  of  air  must  have  ren- 
dered it  exceedingly  cold.  We  have  endeavoured  to 
rouse  some  of  these  from  their  semi-torpidity  by  keep- 
ing them  in  a  warm  room;  but  though  they  would 
make  a  few  lethargic  and  unwilling  movements,  none 
of  them  would  eat,  and  the  change  always  proved 
fatal.* 

We  might  be  led  from  this  instance  to  conclude 
that  caterpillars,  not  covered  with  hair,  become  tor- 
pid during  winter;  but  such  general  conclusions  from 


o,  Young  caterpillar  of  the  drinker.    6,  the  same  full  grown. 
c,  smooth  "caterpillar  of  the  angle  shades.    J,  the  moth  of  the 

enrnp- 


•  J.  R. 


HYBERNATION  OF  CATERPILLARS.       195 

particular  facts  seldom  accord  with  actual  nature,  and 
ought  never  to  be  indulged  in  by  naturalists  who  study 
accuracy.  Another  caterpillar,  not  uncommon  in 
gardens,  on  the  hollyhock  and  other  plants,  would  at 
once  disprove  such  an  inference:  we  allude  to  that  of 
the  angle  shades  (Phlogophora  meticulosa,  OCHSEN- 
HEIMER).  This  caterpillar,  which  is  exceedingly 
smooth,  and  is  remarkable  for  changing  in  its  last 
moult  from  a  clear  green  to  a  yellowish  brown,  we 
have  found  during  the  whole  winter  in  the  folds  of  the 
fresh  leaves  of  hollyhocks,  cabbage-lettuce,  savoys, 
&c,  quite  lively,  and  feeding  in  open  weather  by  no 
means  sparingly.  Its  defence  from  cold  may  perhaps 
consist  in  a  superabundant  supply  of  fat,  which  we 
may  infer  that  it  possesses  from  the  soft  flabby  aspect. 
It  is  this  circumstance  which  seems  to  protect  whales 
from  the  polar  cold;  as  well  as  bears  during  their  tor- 
pidity. 

Some  caterpillars  seem  to  have  no  less  power  of 
resisting  severe  cold  than  eggs;  as  authentic  instan- 
ces are  recorded  of  their  revival  after  being  frozen 
stiff,  —  a  circumstance  also  reported  of  some  serpents 
in  North  America.*  Dr  Lister  in  this  way  revived 
caterpillars  frozen  so  hard  as  to  chink  like  stones  when 
thrown  into  a  glass ;|  and  Mr  Stickney  exposed  some 
grubs  of  a  common  crane-fly  (  Tipula  oleracea,  LINN.) 
to  a  severe  frost,  till  they  were  congealed  into  masses 
of  ice,  yet  several  of  them  survived. J  Reaumur, 
however,  was  unsuccessful  in  similar  experiments  on 
the  gregarious  moth  of  the  fir  (C'nethocampa  Pilyo- 
campa,  STEPHENS),  so  celebrated  among  the  ancients 
as  a  poison;^  for  none  of  them  survived  a  cold  of  2° 
below  zero/Fahr.,  by  which  they  were  frozen  toice.|| 

*  John  Hunter,  Obs.  on  Anim.  F.con.  p.  99. 
t  Goedart,  Insect,  p.  79.         |  Kirby  and  Spcnce,  Intr.  ii,  p. 
453. 
§  Plin.  Hist.  Nat.  38,  9.  II  Mem.  ii. 


CHAPTER  VIII. 

Voracity  of  Caterpillars,  Grubs,  and  Maggots. 

INSECTS,  in  the  early  stage  of  their  existence,  may 
be  compared  to  an  Indian  hunter,  who  issues  from  his 
hut,  as  they  do  from  the  egg,  with  a  keen  appetite. 
As  soon  as  he  is  successful  in  finding  game,  he  gorges 
himself  till  he  can  eat  no  more,  and  then  laying  him 
down  to  sleep,  only  bestirs  himself  again  to  go  through 
a  similar  process  of  gorging  and  sleeping;  just  so  the 
larvae  of  insects  doze  away  a  day  or  more  when  cast- 
ing their  skins,  and  then  make  up  for  their  long  fast 
by  eating  with  scarcely  a  pause.  Professor  Bradley 
calculates  (though  upon  data  somewhat  questionable) 
that  a  pair  of  sparrows  carry  to  their  young  about  three 
thousand  caterpillars  in  a  week;*  but  this  is  nothing 
when  compared  with  the  voracity  of  caterpillars.  Of 
the  latter  we  have  more  accurate  calculations  than  that 
of  Bradley,  who  multiplied  the  number  of  caterpillars 
which  he  observed  taken  in  one  hour  by  the  hours  of 
sunlight  in  a  week.  Redi  ascertained  by  experiment 
that  the  maggot  of  the  common  blow-fly  (Musca  car- 
naria)  becomes  from  140  to  200  times  heavier  within 
twenty-four  hours  ;f  and  the  cultivators  of  silk-worms 
know  the  exact  quantities  of  leaves  which  their  broods 
devour.  c  The  result,'  says  Count  Dandolo,  '  of  the 
most  exact  calculations  is,  that  the  quantity  of  leaves 
drawn  from  the  tree  employed  for  each  ounce  of  eggs 
amounts  to  1609  Ibs,  8oz;  divided  in  the  following  man- 


*  Account  of  the  Works  of  Nature. 
t  Esperienze  de  Insetti,  p.  23. 


VORACITY  OF  CATERPILLARS.         197 

Sorted  leaves.  Refuse. 

Ibs    oz  Ibs    oz 

First  age,                                                              60  18 

Second  age,                                                          18     0  30 

Third  age,                                                          60     0  90 

Fourth  age,                                                        180     0  27     0 

Fifth  age,                                                       1098     0  102     0 

Per  ounce  of  eggs  of  sorted  leaves,      Ibs  1362     0     142     8 
Refuse,  142     8 

Lost  from  the  leaves  by  evaporation,  &c,    105     0 

1609~~8 

He  adds  to  this  curious  taj)le,  that  from  the  1362  Ibs 
of  sorted  leaves  given  to  the  caterpillars,  it  is  neces- 
sary to  deduct  155  Ibs,  7  oz,  4  drs  of  litter,  consist- 
ing of  fragments  of  uneaten  leaves,  stalks,  fruit,  &c, 
and  consequently  that  they  actually  devour  only  1206 
Ibs,  4  oz,  4  drs.  It  is  necessary  also  to  mention  that 
of  this  quantity  745  Ibs,  8  oz  of  dung  are  carried  from 
the  hurdles;  and  consequently  there  is  only  digested 
771  Ibs,  7  oz,  4  drs  of  pure  leaves,  which  produce 
120  Ibs  of  silk  cocoons, — giving  a  loss  by  evaporation 
from  the  worms  in  gas  and  vapour  of  496  Ibs,  4  oz, 
nearly  three  parts  of  this  loss  occurring  in  the  six  last 
days  of  the  fifth  age.*  These  deductions,  however, 
do  not  affect  the  amount  eaten  by  the  caterpillars  pro- 
duced from  1  oz  of  eggs,  which  is  upwards  of  1200 
Ibs.  A  single  silk-worm,  as  we  before  mentioned, 
consumes  within  thirty  days  about  60,000  times  its 
primitive  weight. 

When  we  take  these  facts  into  consideration,  we 
need  not  be  surprised  at  the  extensive  ravages  com- 
mitted by  other  caterpillars,  many  of  which  are  much 
larger  than  the  silk-worm,  and  all  of  them  produced 
in  broods  of  considerable  numbers.  Mr  Stephens, 
in  his  valuable  catalogue  of  British  insects,  a  work  of 

*  Count  Dandolo's  Art  of  rearing  Silk- Worms,  p.  322-24, 
Eng.  Transl. 

VOL.    VI.  17* 


198  INSECT    TRANSFORMATIONS. 

very  extraordinary  accuracy,  enumerates  nearly  2000 
species  of  native  moths  and  butterflies;  and  as  the  fe- 
males of  these  are  for  the  most  part  very  prolific,  we 
have  little  reason  to  be  surprised  at  the  occasional 
extent  of  their  depredations.  The  2000  species  just 
mentioned  are,  besides,  not  more  than  a  fifth  of  our 
native  insects,  most  of  the  grubs  and  maggots  of  which 
are  exceedingly  voracious  and  destructive. 

It  appears  to  be  indispensable  for  most  insects  to  feed 
copiously  during  their  larva  state,  in  order  to  supply  a 
store  of  nutriment  for  their  subsequent  changes;  for 
many  of  them  eat  nothing,  and  most  of  them  little,  after 
they  have  been  transformed  into  pupae  and  perfect  in- 
sects. What  is  no  less  wonderful,  a  corresponding 
change  takes  place  in  the  internal  formation  of  their  or- 
gans of  digestion.  A  caterpillar  will,  as  we  have  seen, 
devour  in  a  month  60,000  times  its  own  weight  of 
leaves,  while  the  moth  or  the  butterfly  into  which  it  is 
afterwards  transformed  may  not  sip  a  thousandth  part 
of  its  weight  of  honey  during  its  whole  existence. 
JVow,  in  the  caterpillar,  nature  has  provided  a  most 
capacious  stomach,  which,  indeed,  fills  a  very  large 
portion  of  its  body;  but  in  the  butterfly  the  stomach  is 
diminished  to  a  thread.  By  a  series  of  minute  dis- 
sections, conducted  with  great  skill,  Heroldt  traced 
these  changes,  as  they  successively  occur,  from  the 
caterpillar  to  the  butterfly.  In  the  caterpillar  he  found 
the  gullet,  the  honey  stomach,  the  true  stomach,  and 
the  intestines  capacious.  Two  days  after  its  first 
change  all  these  are  visibly  diminished,  as  well  as  the 
silk  reservoirs,  which,  in  a  chrysalis  eight  days  old, 
have  wholly  disappeared;  while  the  base  of  the  gullet 
is  dilated  into  a  crop,  and  the  stomach  still  more  con 
tracted  into  a  spindle  form.  When  near  its  change 
into  the  perfect  insect  the  gullet  is  still  more  drawn 
out,  while  the  crop,  still  small,  is  now  on  one  side  of 


VISCERA    OF    THE    COSSUS.  199 

View  of  the  upper  side.  View  of  the  under  side. 


Aj  B,  C,  The  aesopha- 
gus  and  its  appendages. 

D,  E,  The  stomach  5 
—  a  pair    of   muscles 
wind  spirally  jound  it, 
and  by   their  contrac- 
tion   squeeze    the    di- 
gested   food    into    the 
intestines. 

E,  F,  The  first  large 
intestine.   F,G,  the  se- 
cond.   G,  H,  the  third. 

1,1,  The  six  smali  in- 
testines. 


Viscera  of  the  Cossus. 


200 


INSECT  TRANSFORMATIONS. 


A,  A,  Caterpillar  of  Vanessa  urticae  magnified,  a  — fr,  the  intes 
tines  of  the  same,  a,  the  gullet.  6  b  b  b,  pulmonary  tn!-es.  c  c, 
ligament  of  the  stomach,  d  d  d  d,  transparent  rings  of  the  same. 
e  e,  small  intestines.  //,  their  origin,  g  g  h  A,  their  windings.  »  *, 
the  rectum. 


INTESTINAL    STRUCTURE. 


201 


the  gullet;  and  in  the   butterfly    is  enlarged  into  a 
honey  stomach 


Intestinal  canals  of  the  caterpillar,  pupa,  and  butterfly. 

1.  Caterpillar.    «,  the  oesophagus.    6,    the  stomach,    c  rf,   the 

two  large  intestines. 

2.  Pupa  two  days  old.    #,  the  oesophagus.     6,  the  stomach,    c  d 

the  two  large  intestines. 

3.  Pupa  eight  days  old.    a,  dilation  of  the  oesophagus,  forming 

the  crop  or  honey-stomach. 

4.  Pupa  immediately  before  its  transformation.    «,  the  honey- 

stomach  become  a  lateral  appendage  of  the  oesophagus.    6 
the  stomach,     c  d,  the  large  intestines. 

5.  Butterfly,    a,  honey-stomach.    6,  the  digesting  stomach,    c  d, 

the  large  intestines,  become  very  long. 

It  is  remarkable  that  in  men  of  such  extraordinary 
appetite  as  amounts  to  a  disease  (Bulimia,  CULLEN), 
the  natural  capacity  of  the  stomach,  which,  accord- 
ing to  Blumenbach,  contains  about  three  pints,* 
is  very  much  enlarged.  This  was  peculiarly  the 
case  with  Tarare,  an  Italian  juggler,  who,  from  swal- 
lowing flints,  whole  baskets  of  fruit,  &c,  seems 
to  have  enlarged  the  capacity  of  his  stomach  so  as 
to  render  his  appetite  insatiable.  M.  Tessier,  of  the 
Infirmary  at  Versailles,  where  Tarare  died  of  con- 
sumption, found  on  examination  that  his  stomach 


Blumenbach,  Physiol.,  s.  xxiii. 


202  INSECT    TRANSFORMATIONS. 

was  prodigiously  distended.*  The  same  must  have 
been  the  case  with  the  French  prisoner  at  Liverpool, 
who,  on  the  testimony  of  Dr  Cochrane,  consumed, 
in  one  day,  sixteen  pounds  of  raw  meat  and  tallow 
candles,  besides  five  bottles  of  porter.t 

The  mandibles  of  caterpillars,  which  do  not  act 
perpendicularly  like  the  jaws  of  quadrupeds,  but  ho- 
rizontally, are  for  the  most  part  very  sharp  and  strong, 
being  of  a  hard,  horny  substance,  arid  moved  by 
powerful  muscles.  They  are,  for  the  most  part, 
slightly  bent  in  the  form  of  a  reaping-hook;  having 
the  concavity  indented  with  tooth-shaped  projections, 
formed  out  of  the  substance  of  the  jaw,  and  not  socketed 
as  the  teeth  of  quadrupeds.  These  are  made  to  meet 
like  the  blades  of  a  pair  of  pincers;  and  in  some  cases 
they  both  chop  and  grind  the  food.J  Besides  these 
there  is  a  pair  of  jaws  (maxillae)  placed  on  each  side 
of  the  middle  portion  of  the  under  lip;  and  from  their 
being  of  a  softer  substance  they  seem  to  be  more  for 
the  purpose  of  retaining  the  foodn  than  for  mastication. 
This  formidable  apparatus  for  masticating  ( Troplii) 
is  well  adapted  to  supply  the  large  demands  of  the 
capacious  stomachs  of  larvae;  and  when  we  consider 
that  all  of  them  are  employed  in  eating  at  least  for 
ten  or  twelve  hours  in  the  day,  and  a  great  number 
during  the  night,  we  need  not  wonder  at  their  ex- 
tensive ravages  upon  the  substances  on  which  they 
feed.  It  may  be  interesting,  however,  to  give  a  few 
examples  of  their  destructiveness;  and  with  this  view 
it  will  be  convenient  to  consider  them  under  the  three 
popular  names  of  caterpillars,  grubs,  and  maggots. 

CATERPILLARS. 
The  ravages  of  caterpillars  are  amongst  the  most 

*  M.  Percy  in  Rapport  d'Institute  Nationelle. 
+  Med.  and  Phys.  Journ.,  iii,  209. 
%  Cuvier,  Anat.  Com.,  iii,  322. 


RAVAGES    OF    CATERPILLARS.  203 

conspicuous  of  insect  depredations,  in  consequence 
of  their  being  committed  upon  the  leaves  of  trees, 
bushes,  and  plants,  which  are  often  stripped  as  bare 
as  in  winter.  .Even  the  smaller  sorts  of  caterpillars 
become,  from  their  multiplicity,  sometimes  as  destruc- 
tive as  those  which  are  of  considerable  magnitude. 
During  the  summer  of  1827  we  were  told  that  an  ex- 
traordinary blight  had  suddenly  destroyed  the  leaves 
of  all  the  trees  in  Oak  of  Honour  Wood,  Kent.  On 
going  thither,  we  found  the  report  had  been  little  ex- 
aggerated; for  though  it  was  <  in  the  leafy  month  of 
June,'  there  was  scarcely  a  leaf  to  be  seen  on  the 
oak-trees,  which  constitute  the  greater  portion  of  the 
wood.  But  we  were  rather  surprised  when  we  dis- 
covered, on  examination,  that  this  extensive  destruc- 
tion had  been  effected  by  one  of  the  small  solitary 
leaf-rollers  ( Tortrix  viridana,  HAWORTH)  ;*  for  one 
of  this  sor;  seldom  consumes  more  than  four  or  five 
leaves,  if  so  much,  during  its  existence.  The  num- 
ber, therefore,  of  these  caterpillars  must  have  been 
almost  beyond  conception;  and  that  of  the  moths,  the 
previous  year,  must  also,  have  been  very  great:  for  the 
mother  moth  only  lays  from  fifty  to  a  hundred  eggs, 
which  are  glued  to  an  oak  branch,  and  remain  during 
the  winter.  It  is  remarkable  that  in  this  wood  during 
the  two  following  summers  these  caterpillars  did  not 
abound. "f 

Instances,  like  this,  however,  from  solitary  species, 
are,  we  believe,  less  common  than  those  of  the  rava- 
ges of  gregarious  caterpillars.  In  1826,  colonies  of 
the  buff-tip  (Pygccra  bucephala,  OCHSENHEIM.)  were 
in  some  parts  of  the  country  very  abundant.  We  re- 
marked them  particularly  at  Harrow-on-the  Hill,  and 
at  Compton-Basset  in  Wiltshire.  From  their  feeding 
in  company,  they  strip  a  tree,  branch  after  branch, 

*  See  figures  of  this  caterpillar  and  its  moth  in  *  Insect 
Architecture,'  pp.  162-3. 
t  J.  R. 


204  INSECT    TRANSFORMATIONS. 

scarcely  leaving  the  fragment  of  a  leaf,  till  a  great 
portion  of  it  is  completely  bare.  Some  of  the  magni- 
ficent beeches  in  Compton  Park,  from  this  cause,  ap- 
peared with  the  one -half  of  their  branches  leafless 
and  naked,  while  the  other  half  was  untouched.  Be- 
sides the  beech,  these  caterpillars  feed  on  the  oak,  the 
lime,  the  hazel,  the  elm,  and  the  willow.  When 
newly  hatched  they  may  be  readily  discovered,  from 
their  singular  manner  of  marshalling  themselves,  like 
a  file  of  soldiers,  on  a  single  leaf,  only  eating  it  half 
through;  and  in  their  more  advanced  stage,  their 
gaudy  stripes  of  yellow  and  black  render  them  very 
conspicuous  on  the  branches  which  they  have  nearly 
stripped  bare.  The  cuckoo  feeds  as  greedily  upon 
them  as  they  do  on  leaves,  and  may  be  seen  early  in 


Ravages  of  the  buff  tip  caterpillar  (Py^tzru  bucephala).  a,  the 
full-grown  caterpillar.  6,  the  moth,  c  c,  a  line  of  young  cater- 
pillars, advancing  along  a  leaf  and  devouring  it  half  through  as 
they  march,  d,  the  eggs. 


RAVAGES    OF    CATERPILLARS.  205 

the  morning  perched  in  the  midst  of  their  colonies, 
and  devouring  them  hy  dozens.* 

Those  caterpillars  which  feed  upon  fruit-trees  and 
hedge  shrubs  are  still  more  likely  to  attract  attention; 
since,  when  any  of  these  are  abundant,  it  is  scarcely 
possible  to  stir  out  of  doors  without  observing  them. 
Thus,  in  the  suburbs  of  London,  in  the  summer  of 
1829,  not  only  the  orchards  and  gardens,  but  every 
hedge,  swarmed  with  the  lackey  caterpillars  (  Clisw- 
campa  neustria),  which  are  what  naturalists  term 
polyphagous  feeders,  that  is,  they  do  not  confine  them- 
selves to  a  particular  sort  of  tree,  but  relish  a  great 
number.  The  hawthorn,  the.  black  thorn,  and  the 
oak,  however,  seem  to  be  most  to  their  taste;  while 
they  are  rare  on  the  willow,  and  we  have  never  ob- 
served them  on  the  poplar,  or  the  elder. 

Another  of  what  may  be  appropriately  termed  the 
encamping  caterpillars,  of  a  much  smaller  size, 
and  of  a  different  genus,  is  the  small  ermine  (  Ypono- 
meuta  padella),  which  does  not,  besides,  feed  quite 
so  indiscriminately;  but  when  the  bird-cherry  (Pru- 
nus  padus\  its  peculiar  food,  is  not  to  be  had,  it  will 
put  up  with  black  thorn,  plum-tree,  hawthorn,  and 
almost  any  sort  of  orchard  fruit-tree.  With  respect 
to  such  caterpillars  as  feed  on  different  plants,  Reau- 
mur and  De  Geer  make  the  singular  remark,  that  in 
most  cases  they  would  only  eat  the  sort  of  plant  upon 
which  they  were  originally  hatched.")*  We  verified 
this,  in  the  case  of  the  caterpillar  in  question,  upon 
two  different  nests  which  we  took,  in  1806,  from  the 
bird-cherry  at  Crawfbrdland,  in  Ayrshire.  Upon 
bringing  these  to  Kilmarnock,  we  could  not  readily 
supply  them  with  the  leaves  of  this  tree;  and  having 
then  only  a  slight  acquaintance  with  the  habits  of  in- 
sects, and  imagining  they  would  eat  any  sort  of  leaf, 
we  tried  them  with  almost  every  thing  green  in  the 

*  J.  R.  t  De  Geer,  Mem.  i,  319. 

VOL.   VI.  18 


206  INSECT   TRANSFORMATIONS. 

vicinity  of  the  town;  but  they  refused  to  touch  any 
which  we  offered  them.  After  they  had  fasted  several 
days,  we  at  length  procured  some  fresh  branches  of 
the  bird-cherry,  with  which  they  gorged  themselves 
so  that  most  of  them  died.  Last  summer  (1829)  we 
again  tried  a  colony  of  these  caterpillars,  found  on  a 
seedling  plum-tree  at  Lee,  in  Kent,  with  black  thorn, 
hawthorn,  and  many  other  leaves,  and  even  with  those 
of  the  bird-cherry;  but  they  would  touch  nothing  ex- 
cept the  seedling  plum,  refusing  the  grafted  varieties.* 


Encampment  of  the  caterpillar  of  the  small  ermine  (Yponomeuta 
paddla)  oik  the  Siberian  crab. 

A  circumstance  not  a  little  remarkable  in  so  very 
nice  a  feeder  is,  that  in  some  cases  the  mother  moth 
will  deposit  her  eggs  upon  trees  not  of  indigenous 
growth,  and  not  even  of  the  same  genus  with  her 


J.  R, 


RAVAGES    OF    CATERPILLARS.  207 

usual  favourites.  Thus,  in  1825,  the  cherry-apple, 
or  Siberian  crab  (Pyrus  prunifolia,  WILLDENOW), 
so  commonly  grown  in  the  suburbs  of  London, 
swarmed  with  them.  On  a  single  tree  at  Islington, 
we  counted  above  twenty  nests,  each  of  which  would 
contain  from  fifty  to  a  hundred  caterpillars;  and 
though  these  do  not  grow  thicker  than  a  crow-quill, 
so  many  of  them  scarcely  left  a  leaf  undevoured,  and, 
of  course,  the  fruit,  which  showed  abundantly  in 
spring,  never  came  to  maturity.  The  summer  fol- 
lowing they  were  still  more  abundant  on  the  haw- 
thorn hedges,  particularly  near  the  Thames,  by  Bat- 
tersea  and  Richmond,  Since  then  we  have  only  seen 
them  sparingly;  and  last  summer  we  could  only  find 
the  single  nest  upon  which  we  tried  the  preceding  ex- 
periment.* This  present  spring  (1830)  they  have 
again  appeared  in  millions  on  the  hedges. 

Reaumur  says  that  in  some  years  they  were  ex- 
ceedingly destructive  to  his  apple-trees,  though  they 
did  not  touch  his  pears,  plums,  or  apricots,f  which 
agrees  precisely  with  our  own  remarks.  We  are  well 
aware  that  there  are  several  species  of  the  small  er- 
mines, all  similar  in  manners,  such  as  the  one  which 
feeds  on  the  spindle- tree,  (Euonymus},  and  pro- 
duces the  prettiest  moth  of  the  genus  ( Yponomeuta 
Euonymellaj)  but  our  preceding  remarks  all  apply 
to  one  species. 

In  1829  we  remarked  a  very  extraordinary  num- 
ber of  webs  of  some  similar  caterpillar,  of  which  we 
did  not  ascertain  the  species,  on  the  willows  in  Hol- 
land and  the  Netherlands,  from  Amsterdam  to 
Ostend.  In  some  districts,  particularly  near  Bruges 
and  Rotterdam,  the  leaves  were  literally  stripped 
from  whole  rows  of  trees;  while  other  rows,  at  no 
considerable  distance,  were  entirely  free  from  their 
ravages.  A  foreign  naturalist,  quoted  by  Harris  in 

J.  R.  t  Reaumur,  Mem.  ii,  198. 


208  INSECT    TRANSFORMATIONS. 

his  Aurelian,  says,  that  the  caterpillar  of  the  Camber- 
well  beauty  (Vanessa  Jlntwpa),  which  feeds  grega- 
riously on  the  willow,  sometimes  defoliates  the  trees 
of  a  whole  district  in  the  Low  Countries;  but  the 
ravages  observed  by  us  were  evidently  made  by  the 
caterpillars  of  some  small  moth.* 

None  of  the  preceding  details,  however,  appear  so 
striking  as  what  is  recorded  of  the  brown-tail  moth 
(Porthesia  auriflua},  by  Mr  W.  Curtis,!  whose 
multitudinous  colonies  spread  great  alarm  over  the 
country, in  the  summer  of  1782.  This  alarm  was 
much  increased  by  the  exaggeration  and  ignorant  de- 
tails which  found  their  way  into  the  newspapers.  The 
actual  numbers  of  these  caterpillars  must  have  been 
immense,  since  Curtis  says,  i  in  many  of  the  parishes 
near  London  subscriptions  have  been  opened,  and 
the  poor  people  employed  to  cut  off  the  websj  at  one 
shilling  per  bushel,  which  have  been  burnt  under  the 
inspection  of  the  churchwardens,  overseers,  or  beadle 
of  the  parish:  at  the  first  onset  of  this  business  four- 
score bushels,  as  I  was  most  credibly  informed,  were 
collected  in  one  day  in  the  parish  of  Clapham.7 

It  is  not,  therefore,  very  much  to  be  wondered  at, 
that  the  ignorant,  who  are  so  prone  to  become  the 
victim  of  groundless  fears,  should  have  taken  serious 
alarm  on  having  so  unusual  a  phenomenon  forced 
upon  their  attention.  Some  alarmists  accordingly 
asserted  that  the  caterpillars  c  were  the  usual  presage 
of  the  plague  j'  and  others  that  they  not  only  pre- 
saged it,  but  would  actually  cause  it,  for  *  their 
numbers  were  great  enough  to  render  the  air  pesti- 
lential,5 while,  to  add  to  the  mischief,  '  they  would 
destroy  every  kind  of  vegetation,  and  starve  the  cattle 
in  the  fields.'  '  Almost  every  one/  adds  Curtis, 

*  J.  R. 

t  Curtis,  Hist,  of  Brown-tail  Moth,  4to.  London,  1782. 
t  See  Insect  Architecture,  page  330,  for  a  figure  of  the  nest. 


RAVAGES    OF    CATERPILLARS.  209 

c  ignorant  of  their  history,  was  under  the  greatest 
apprehensions  concerning  them;  so  that  even  prayers 
were  offered  up  in  some  churches  to  deliver  the 
country  from  the  apprehended  approaching  cala- 
mity.' 

It  seems  to  have  been  either  the  same  caterpillar, 
or  one  very  nearly  allied  to  it,  probably  that  of  the 
golden-tail  (Porthesia  Chrysorrhcea),  which  in  1731- 
2,  produced  a  similar  alarm  in  France.  Reaumur,  on 
going  from  Paris  to  Tours,  in  September  1730,  found 
every  oak,  great  and  small,  literally  swarming  with 
them,  and  their  leaves  parched  and  brown  as  if  some 
burning  wind  had  passed  over  them;  for  when  newly 
hatched,  like  the  young  buff-tips,  they  only  eat  one 
of  the  membranes,  of  the  leaf,  and  of  course  the  other 
withers  away*  These  infant  legions,  under  the  shel- 
ter of  their  warm  nests,*  survived  the  winter  in  such 
numbers,  that  they  threatened  the  destruction  not 
only  of  the  fruit-trees,  but  of  the  forests,  —  every  tree, 
as  Reaumur  says,  being  over-run  with  them.  The 
Parliament  of  Paris  thought  that  ravages  so  widely 
extended  loudly  called  for  their  interference,  and 
they  accordingly  issued  an  edict,  to  compel  the  people 
to  uncaterpillar  (decheniller)  the  trees;  which  Reau- 
mur ridiculed  as  impracticable,  at  least  in  the  forests. 
About  the  middle  of  May,  however,  a  succession  of 
cold  rains  produced  so  much  mortality  among  the 
caterpillars,  that  the  people  were  happily  released 
from  the  edict;  for  it  soon  became  difficult  to  find  a 
single  individual  of  the  species. "f  In  the  same  way  the 
cold  rains,  during  the  summer  of  1829,  seem  to  have 
nearly  annihilated  the  lackeys,  which  in  the  early  part 
of  the  summer,  swarmed  on  every  hedge  around 
London. J  The  ignorance  displayed  in  France  at  the 
time  in  question,  was  not  inferior  to  that  recorded  by 

*  Sec  Insect  Architecture,  p.  331,  for  a  figure. 
I  Reaumur,  ii,  p.  137.         £  Insect  Architecture,  p.  329. 

VOL.  VI.  18* 


210  INSECT    TRANSFORMATIONS. 

Curtis;  for  the  French  journalists  gravely  asserted 
that  part  of  the  caterpillars  were  produced  by  spiders; 
and  that  these  spiders,  and  not  the  caterpillars,  con- 
structed the  webs  of  the  slime  of  snails,  which  they 
were  said  to  have  been  seen  collecting  for  the  pur- 
pose! 'Verily,'  exclaims  Rraumur,  ;  there  is  more 
ignorance  in  our  age  than  one  might  believe.' 

It  is  justly  remarked  by  Curtis,  that  the  caterpillar 
of  the  brown-tail  moth  is  not  so  limited  a  feeder  as 
some,  nor  so  indiscriminate  as  others;  but  that  it  always 
confines  itself  to  trees  or  shrubs,  and  is  never  found  on 
herbaceous  plants,  whose  low  growth  would  seldom 
supply  a  suitable  foundation  for  its  web.  Hence  the 
absurdity  of  supposing  it  would  attack  the  herbage 
of  the  field,  and  produce  a  famine  among  cattle. 
Curtis  says,  it  is  found  on  the  c  hawthorn  most  plen- 
tifully, oak  the  same,  elm  very  plentifully,  most  fruit- 
trees  the  same,  black  thorn  plentifully,  rose-trees  the 
same,  bramble  the  same,  on  the  willow 'and  poplar 
scarce.  None  have  been  noticed  on  the  elder,  walnut, 
ash,  fir,  or  herbaceous  plants.  With  respect  to  fruit- 
trees  the  injuries  they  sustain  are  most  serious,  as,  in 
destroying  the  blossoms  as  yet  in  the  bud,  they  also 
destroy  the  fruit  irj  embryo;  the  owners  of  orchards, 
therefore,  have  great  reason  to  be  alarmed.' 

The  sudden  appearance  of  great  numbers  of  these 
caterpillars  in  particular  years,  and  their  scarcity  in 
others,  is  in  some  degree  explained  by  a  fact  stated 
by  Mr  Salisbury.  '  A  gentleman  of  Chelsea,'  he 
says,  '  has  informed  me  that  he  once  took  a  nest 
of  moths  and  bred  them;  that  some  of  the  eggs 
came  the  first  year,  some  the  second,  and  others  of 
the  same  nest  did  not  hatch  till  the  third  season.'* 
We  reared,  during  1829,  several  nests  both  of 
the  brown-tails  and  of  the  golden-tails,  and  a  num- 
ber of  the  females  deposited  their  eggs  in  our  nurse- 

*  Salisbury,  Hints  on  Orchards,  p.  53. 


RAVAGES    OF    CATERPILLARS.  211 

cages  ;  but,  contrary  to  the  experiment  just  quoted, 
all  of  these  were  hatched  during  the  same  autumn.* 
The  difference  of  temperature  and  moisture  in  par- 
ticular seasons  may  produce  this  diversity. 

An  alarm,  similar  to  those  we  have  recorded,  was 
produced  in  France  in  1735  by  the  green  striped 
caterpillars  of  a  moth  very  common  in  Britain,  called 
by  collectors,  from  a  mark  on  its  upper  wings,  the  Y,  or 
more  properly  the  y  moth  (Plusia  Gamma,  OCHS.). 
Though  ranked  in  some  classifications  amongst  the 
nocturnal  moths,  it  flies  chiefly  by  day,  and  may  be  seen 
in  Battersea-fields,  or  other  moist  meadows,  flitting 
from  herb  to  herb  and  flower  to  flower,  in  short  and 
low  flights;  for  it  seldom  soars  higher  than  the  tallest 
grass-stem,  or  the  crimson  flower-heads  of  the  knap- 
weed, upon  whose  honey  it  sometimes  regales,  re- 
maining on  the  wing  all  the  while  it  is  sipping  it. 
During  the  cold  rainy  summer  of  1829  it  was  almost 
the  only  moth  which  appeared  plentiful. "j*  At  least 
two  broods  seem  to  be  produced  during  the  season  ; 
which  may  account  for  its  being  found  from  May  till 
the  setting-in  of  the  winter  frosts. 

Notwithstanding  it  being  so  plentiful,  however,  we 
have  not  heard  of  its  having  ever  been  so  destruc- 
tive here  as  in  France,  were,  as  usual,  the  most 
improbable  causes  were  assigned  for  its  increase. 
*  In  some  places,'  says  Reaumur,  c  they  assured  me 
they  had  seen  an  old  soldier  throw  the  spell  ;  and  in 
other  places  an  ugly  and  mischievous  old  woman  had 
wrought  all  the  evil.'J  These  supposed  supernatu- 
ral agents,  however,  must  have  been  either  very  nu- 
merous or  very  active  to  fill,  not  only  the  gardens, 
but  every  field,  with  legions  of  those  caterpillars,  which 
devoured  almost  every  green  thing,  and  left  only  the 
stalks  as  monuments  of  their  devastation.  The 
alarm  proceeded  farther,  for  it  began  to  be  whispered 

*  J.  R.  t  J.  R.  $  Reaumur,  ii,  336. 


INSECT    TRANSFORMATIONS. 

that  they  were  poisonous  ;  and  many  were  in  conse- 
quence afraid  to  touch  soups  or  salads.  Reaumur 
thought  it  incumbent  on  him  to  refute  this  notion  at 
some  length  ;  but  we  cannot  accept  his  doctrine  as 
very  palatable,  when  he  tells  us  that  few  dishes  of  soup 
or  salad  are  ever  prepared  without  containing  cater- 
pillars, and  yet  all  the  world  are  not  poisoned  there- 
by, any  more  than  by  eating  oysters  or  viper  broth. 
He  endeavoured  also  to  account  by  calculation  for 
their  excess,  from  the  data  of  the  female  moth  lay- 
ing about  four  hundred  eggs.  Now,  if  there  were 
only  twenty  caterpillars  distributed  in  a  garden,  and 
all  lived  through  the  winter,  and  became  moths  in 
the  succeeding  May,  the  eggs  laid  by  these,  if  all  fer- 
tile, would  produce  800,000,  a  number  much  more 
than  sufficient  to  effect  great  destruction.*  Did  not 
Providence,  therefore  put  causes  in  operation  to  keep 


Transformations  of  the  y  muih  (Phisin  Gamir>n).  «,  the  r<r;r,  featly 
magnified,  on  a  morsel  of  l«af.  Z>,  the  e™r  on  n  lea*1,  i  mural  size,  r,  the 
larva.  <?,  the  pupa,  e,  the  moth. 

*  Rv'amnur,  ii,  327. 


RAVAGES    OF    CATERPILLARS.  213 

them  in  due  bounds,  the  caterpillars  of  this  moth  alone, 
leaving  out  of  consideration  the  2000  other  British 
species,  would  soon  destroy  more  than  half  of  our  ve- 
getation. 

The  caterpillar  just  mentioned,  amongst  other  pot- 
herbs attacks  coleworts  and  cabbage;  and  may  some- 
times be  found  there  along  with  another,  not  uncom- 
mon, but  seldom  very  destructive,  called  by  collectors 
the  burnished  brass  (Plusia  chrysitis),  which  differs 
little  from  the  caterpillar  of  the  y  moth,  except  in  be- 
ing of  a  brighter  green.  Another,  called  the  old  gen- 
tlewoman (Mamestra  brassicce,  TREITSCHE),  is  so 
destructive  to  cabbages  in  Germany,  that  the  gar- 
deners gather  whole  baskets  full  and  hnry  them  j 
but  as  Rb'sel  remarks,  they  might  as  well  endeavour 
to  kill  a  crab  by  covering  it  with  sea-water,  for  it 
is  natural  to  them  to  burrow  under  ground  when 
they  change  into  chrysalides.*  We  have  seen  this 
caterpillar,  as  well  as  that  of  the  brown-eye  (Mames- 
tra oleracea\  do  considerable  damage  in  Wiltshire, 
but  nothing  to  what  is  reported  of  it  in  Germany. 

The  leaves  of  cabbages,  cauliflower,  brocoli,  cole- 
worts,  and  turnips,  are  frequently  devoured  to  a 
more  considerable  extent  by  the  sub-gregarious  cater- 
pillars of  the  white  butterflies  (Pontia  brassicce,  P. 
napiy  &c.)  From  the  great  multiplicity  of  the  but- 
terflies, indeed,  and  from  there  being  two  broods  in 
the  year,  we  have  reason  to  wonder  that  their 
ravages  are  not  more  extensive.  But  we  have  re- 
marked, that  they  seem  more  partial  to  wild  than  cul- 
tivated plants  ;  for  we  have  seen,  near  Islington,  the 
oleraceous  weeds,  such  as  rape  (Brassica  napus), 
over-run  with  them  in  the  very  same  fields  with  cul- 
tivated cabbages,  which  were  not  touched  ;|  so  that 
the  caterpillars  are  not  always  so  injurious  as  we 
might  at  first  suppose,  since  in  this  case  they  tend  to 

*  Rosel,  Inseckten,  i,  iv,  170.  t  J.  R. 


214  INSECT    TRANSFORMATIONS. 

keep  down  the  weeds,  while  the  birds  and  the  ichneu- 
mon flies  keep  them  in  check  by  making  prey  of  them. 

The  gregarious  caterpillars  of  an  allied  species, 
called  the  black-veined  white  butterfly  (Pieris  Cra- 
tcegi,  STEPHENS),  is  in  some  seasons  and  districts  no 
less  destructive  to  orchards  and  hawthorn  hedges  than 
the  preceding  ones  are  to  the  kitchen-garden.  Sal- 
isbury, who  wrote  at  Chelsea  in  1815,  says  it  'com- 
mits great  destruction  every  spring,  and  not  only  to 
the  apple-trees,  but  other  kinds  of  fruits.'*  Mr 
Stephens,  writing  in  1827  says,  *  in  June  1810,1 
saw  it  in  plenty  at  Coombe  Wood,  and  in  the  follow- 
ing year  I  captured  several  at  Muswell-hill,  since 
which  time  I  have  not  seen  any  at  large,  'f  Mr 
Haworth  also  says,  c  it  has  not  of  late  years  been 
seen  at  Chelsea,  where  it  formerly  abounded.  We 
have  never  met  with  at  all.  According  to  Salisbury 
the  female  butterfly  lays  her  eggs  near  the  extremity 
of  an  old  rather  than  a  young  branch,  and  covers 
them  with  a  coating  of  gluten,  which  is  both  imper- 
vious to  moisture  and  impenetrable  (this  we  doubt) 
to  the  bills  of  birds.  c  In  this  state,5  he  adds,  '  we 
have  instances  of  their  remaining  without  losing 
their  vitality  for  several  years,  until  a  favourable  op- 
portunity of  their  being  brought  into  existence  ar- 
rives. '  J  The  caterpillars,  which  are  at  first  black  and 
hairy,  live  in  common  in  a  silken  tent.  They  become 
subsequently  striped  with  reddish  brown,  and  disperse 
over  the  trees.  This  caterpillar  and  its  butterfly  are 
figured  in  a  subsequent  page. 

Our  gooseberry  and  red- currant  bushes  are  very 
frequently  despoiled  of  their  leaves,  both  by  the 
speckled  caterpillar  of  the  magpie  moth  (Mraxas 
grossulariata),  and  by  what  Reaumur  terms  the 

*  Hints  on  Orchards,  p.  56. 

1  Illustrations,  i,  Haustellata,  27. 

j  Hints  on  Orchards,  p,  57. 


RAVAGES    OF    CATERPILLARS.  215 

pseudo-caterpillars  of  one  of  the  saw-flies  (Nematus 
Ribesii,  STEPHENS).  The  latter  insect  has  a  flat  yel- 
low body  and  four  pellucid  wings,  the  two  outer  ones 
marked  with  brown  on  the  edge.  In  April  it  issues 
from  the  pupa,  which  has  lain  under  ground  from  the 
preceding  September.  The  female  of  the  gooseberry 
saw-fly  does  not,  like  some  of  the  family,  cut  a  groove 
in  the  branch  to  deposit  her  eggs;  — c  of  what  use, 
then,'  asks  Reaumur,  '  is  her  ovipositor  saw?'*  In 
order  to  satisfy  himself  on  this  point,  he  introduced 
a  pair  of  the  flies  under  a  bell-glass  along  with  a 
branch  bent  from  a  red-currant  bush,  that  he  might 
watch  the  process.  The  female  immediately  peram- 
bulated the  leaves  in  search  of  a  place  suited  to 
her  purpose,  and  passing  under  a  leaf  began  to  lay, 


n  a  a,  Saw-fly  of  the  gooseberry  (Nematus  -Ribesii,  Stephens).  6,  its 
eggs  on  the  nervures  of  a  leaf,  d  d,  the  caterpillars  eating,  c,  one 
rolled  up.  /,  one  extended. 

*  See  Insect  Architecture,  chap,  vii,  for  a  description  of  this 
curious  instrument. 


216  INSECT    TRANSFORMATIONS. 

depositing  six  eggs  within  a  quarter  of  an  hour. 
Each  time  she  placed  herself  as  if  she  wished  to  cut 
into  the  leaf  with  her  saw  ;  but,  upon  taking  out 
the  leaf,  the  eggs  appeared  rather  projecting  than 
lodged  in  its  substance.  They  adhered  so  firmly, 
however,  that  they  could  not  be  detached  without 
crushing  them.  He  could  not  discover  any  groove;* 
but  we  think  it  likely  that  a  minute  cut  is  made  in 
the  exterior  membrane  of  the  leaf,  the  edges  of  which 
grasp  and  hold  firm  the  part  of  the  egg  which  is 
thrust  into  it  by  the  insect.  Be  this  as  it  may,  the 
caterpillars  are  hatched  in  two  or  three  weeks;  and 
they  feed  in  company  till  after  midsummer,  frequently 
stripping  both  the  leaves  and  fruit  of  an  extensive 
plantation.  The  caterpillar  has  six  legs  and  sixteen 
prolegs,  and  is  of  a  green  colour  mixed  with  yellow, 
and  covered  with  minute  black  dots  raised  like  sha- 
green. In  its  last  skin  it  loses  the  black  dots  and 
becomes  smooth  and  yellowish  white.  The  Caledo- 
nian Horticultural  Society  have  published  a  number 
of  plans  for  destroying  these  caterpillars. 

An  allied  species  of  saw-fly  (Ntmatus  Caprece, 
STEPHENS)  frequently  becomes  extensively  destruc- 
tive to  several  species  of  willow, 'sallow,  and  osier. 
It  is  so  like  that  of  the  gooseberry  and  that  of  the 
willow  (Nematus  salicis),  which  is  not  British,  that  it 
has  been  confounded  with  these  by  Fabricius,  Stew- 
art, Gmelin,  and  other  authors.  In  the  summer  of 
1828,  we  observed  a  considerable  group  of  young 
standards  of  the  golden  osier  (Salix  vitellina},  in  a 
nursery  at  Lewisham,  rendered  quite  leafless  by  these 
caterpillars;  which,  when  feeding,  throw  themselves 
into  singular  postures  by  holding  only  with  their 
fore  feet.  The  fly  -appears  in  spring,  and  places  its 
eggs  in  a  round  patch  on  the  back  of  the  leaf,  and 
not  along  the  nervures,  like  the  gooseberry  saw  fly. 

*  Reaumur,  v,  1 25. 


RAVAGES    OF    CATERPILLARS. 


217 


During  the  three  last  summers,  we  also  remarked 
that  the  alders  (Jllnus  glutinosa]  along  the  banks  of 
the  Ravensbourne,  in  Kent,  were  extensively  stripped 
of  their  leaves  by  a  saw-fly  caterpillar,  very  like  the 
preceding,  but  of  a  larger  size.*  It  appears  to  be 
the  same  as  one  figured  by  Reaumurf  ( Selandria 
Alni  ?  STEPHENS). 


«,  Nematus  cerprece,  on  the  osier  ;  6,  Selandria  nlni  ?  on  the  alder*. 

Another  slimy  caterpillar  of  a  saw-fly,  allied  to 
that  of  the  cherry  (Tenthredo  Cerasi),  is  called  the 
slug  worm  in  North  America,  where  it  has  increased 


*J.  R. 

VOL.   VI. 


Reaumur,  vol.  v,  pi.  11,  fi  .  1,  2. 
19 


218  INSECT    TRANSFORMATIONS. 

so  numerously  as  to  threaten  the  entire  destruction  of 
.  fruit  trees,  including  the  cherry,  plum,  pear,  and 
quince.  Where  they  are  numerous,  the  air  becomes 
loaded  with  a  disagreeable  and  sickly  effluvium.  The 
history  of  this  orchard  pest  has  been  admirably 
written  by  Professor  Peck.* 

When  a  turnip  crop  has  been  fortunate  enough  to 
escape  the  ravages  committed  on  it  in  the  seed  leaf 
by  a  small  jumping  beetle  (Haltica  nemorum,  ILLI- 
GER),  and  by  a  root  weevil  (Nedyus  contractus, 
STEPHENS),  a  no  less  formidable  depredator  some 
times  appears  in  a  caterpillar  belonging  to  the  saw- 
fly  family  (Tenthredinidce},  and  apparently  of  the 
genus  Jfthalia.  An  instance  .is  recorded  by  Mar- 
shall, in  the  Philosophical  Transactions,  of  many 
thousand  acres  having  had  to  be  ploughed  up  on 
account  of  the  devastations  caused  by  these  insects. 
It  is,  he  informs  us,  the  general  opinion  in  Norfolk, 
that  they  come  from  over-sea;  and  a  farmer  averred 
that  he  saw  them  arrive  in  clouds  so  as  to  darken 
the  air,  while  the  fishermen  reported  that  they  had 
repeatedly  witnessed  flights  of  them  pass  over  their 
heads  when  they  were  at  a  distance  from  land.  On 
the  beech  and  the  cliffs,  indeed,  they  lay  in  heaps, 
so  that  they  might  have  been  taken  up  with  shovels; 
while  three  miles  inland  they  crowded  together  like 
a  swarm  of  bees.")" 

We  have  little  doubt,  however,  that  these  details 
are  put  in  an  inverse  order;  as  frequently  occurs  in 
histories  of  the  proceedings  of  insects  by  those  but 
little  acquainted  with  their  habits.  Insects  of  this 
family,  indeed,  seldom  fly  far,  and  could  not  at  all 
events  cross  the  sea,  unless  it  might  be  a  narrow  bay 
or  inlet;  and  if  they  had,  we  ought  to  have  heard  of 
their  departure  as  well  as  their  arrival,  since  their 

*  Nat.  Hist,  of  the  Slug  Worm,  Boston,  1799. 
i  Phil.  Trans,  vol.  Ixxiii,  p.  317. 


RAVAGES  OF    CATERPILLARS.  219 

extraordinary  number  could  not  have  failed  to  at- 
tract public  notice  on  other  shores.  The  nature  of 
these  insects  is  to  lie  in  the  pupa  state  during  the 
winter  under  ground;  and  when,  at  its  appointed 
time,  the  fly  comes  forth,  it  only  lives  to  lay  its  eggs, 
usually  dying  within  a  few  days  or  weeks.  It  must 
have  been,  therefore,  after  the  laying  their  eggs  on  the 
turnips,  and  not  before,  that  clouds  of  the  flies  were 
seen  at  sea  and  on  the  shore,  though  not  arriving, 
but  going  away.  They  were,  doubtless,  impelled  by 
that  restless  desire  of  change  felt  by  all  animals 
when  death  is  approaching,  and  which  in  tropcal 
countries  is  yearly  exemplified  in  the  destruction  of 
locusts,  for  these  always  make  for  the  sea,  and 
perish  there.  But  though  they  were  thus  got  rid 
of  in  August,  1782,  they  left  a  progeny  behind  them 
in  the  black  caterpillars  which  were  hatched  from 
their  eggs.  In  the  summer  of  1783,  accordingly, 
we  are  told  by  Mr  Marshall,  that  whole  districts 
were  ravaged  by  them, — the  descendants,  of  course, 
in  the  second  generation,  of  the  saw-flies  which  pe- 
rished .on  the  beach  and  at  sea  the  preceding  au- 
tumn. 

Some  caterpillars,  which  either  conceal  them- 
selves under  ground,  or  feed  on  roots  and  the  wood 
-of  trees,  do  considerable  injury,  without  apparent 
cause;  and  often  give  occasion  to  the  popular  notions 
respecting  mysterious  blights.  In  this  manner  will 
the  caterpillars  of  the  ghost  moth  (Hepialus  Humuli) 
gnaw  the  roots  of  the  burdock,  and,  what  is  of  more 
consequence,  of  the  hop  plant,  till  the  shoots  are 
weakened  and  the  leaves  droop  in  bright  sunshine. 
We  have  repeatedly  seen,  in  the  gardens  about  Lee, 
a  large  branch  of  the  red-currant  bush,  though  pre- 
viously healthy  and  loaded  with  fruit,  all  of  a  sud- 
den droop  and  wither,  giving  good  cause  to  sur- 
mise, except  in  the  leaves  not  being  brown  or 


220  INSECT    TRANSFORMATIONS. 

parched,  that  it  had  been  struck  with  lightning.  On 
cutting  into  such  branches,  however,  the  cause  was 
uniformly  found  to  be  the  ravages  of  the  caterpillar 
of  the  currant  hawk -moth  (JEgeria  tipuliformis, 
STEPHENS),  which  abounds  in  the  vicinity.  But  we 
have  also  remarked  that  it  only  occasionally  produces 
this  effect  upon  the  trees;  for  several  bushes  upon 
which  we  have  found  old  pupa-cases  projecting  from 
the  bark,  remained  healthy  and  uninjured.*  Sir 
Joseph  Banks  showed  Mr  Kirby  a  currant  branch 
perforated  by  this  caterpillar  to  the  pith,  and  said  the 
size  of  the  fruit  was  in  consequence  diminished.! 
In  Germany  it  is  reported  to  destroy  even  large 
bushes  of  the  red  currant.  There  can  be  no  doubt 
that  the  caterpillars  of  the  goat  moth  frequently 
destroy  willow,  poplar,  and  oak  trees,  of  considerable 
magnitude;  but  the  mother  moth  seems  to  prefer 
laying  her  eggs  upon  those  which  have  already 
begun  to  decay.  A  black  poplar  tree,  not  thicker 
than  a  man's  leg,  and  stripped  on  one  side  of  more 
than  a  foot  of  the  bark,  was  bored  by  above  a  dozen 
caterpillars  of  the  clear  underwing  (JEgeria-  asili- 
formis,  STEPHENS),  without  seeming  to  have  its 
growth  at  all  retarded.  J 

It  does  not  appear  that  a  minute  moth,  called  by 
Leeuwenhoeck,  who  writes  its  history,  the  wolf,  and 
by  Haworth  the  mottled -woollen  (Ph.  Tinea  granella, 
LINNAEUS),  is  so  abundant  in  Britain  as  to  do  much 
damage  to  the  grain  stored  in  granaries,  upon  which 
it  feeds.  But  it  seems  to  have  created  considerable 
alarm  on  the  Continent.  It  has  been  found  near 
London,  and  may  increase  with  us.  The  cater- 
pillar, which  is  smooth  and  white,  ties  together  with 
silk  several  grains  of  wheat,  barley,  rye,  or  oats,  weav- 

*  J,  R.  t  Kirby  and  Spence,  vol.  i.  p.  197, 

t  See  Ins.  Archit.,  p.  192. 


RAVAGES    OF    CATERPILLARS. 


221 


ing  a  gallery  between  them,  from  which  it  projects  its 
head  while  feeding;  the  grains,  as  Reaumur  remarks, 
being  prevented  from  rolling  or  slipping  by  the  silk 
which  unites  them.  He  justly  ridicules  the  absurd 
notion  of  its  filing  off  the  outer  skin  of  the  wheat  by 
rubbing  upon  it  with  its  body,  the  latter  being  the 
softer  of  the  two:  and  he  disproved,  by  experiment, 
Leeuwenhoeck's  assertion  that  it  will  also  feed  on 
woollen  cloth.  It  is  from  the  end  of  May  till  the 
beginning  of  July  that  the  moths,  which  are  of  a 
silvery  gray,  spotted  with  brown,  appear  and  lay  their 
eggs  in  granaries. 

The  caterpillar  of  another  still  more  singular 
grain  moth  (Tinea  Hordei,  KIRBY)  proves  some- 
times very  destructive  to  granaries.  The  mother 
moth,  in  May  or  June,  lays  about  twenty  or  more 
eggs  on  a  grain  of  barley  or  wheat;  and  when  the 
caterpillars  are  hatched  they  disperse,  each  selecting 
a  single  grain.  M.  Reaumur  imagines  that  san- 
guinary wars  must  sometimes  arise,  in  cases  of  pre- 
occupancy,  a  single  grain  of  barley  being  a  rich 


Transformations  of  the  grain  moths,  «,  grain  of  barley  includ- 
ing a  caterpillar  5  ft,  c,  the  grain  cut  across,  seen  to  be  hollowed 
out,  and  divided  by  a  partition  of  silk ;  d,  the  moth  (Tinea 
Hordei) ;  e,  grains  of  wheat  tied  together  by  the  caterpillar  $  fy 
g,  the  moth  (Euplocamus  trranella). 


VOL.    VT. 


19* 


222  INSECT    TRANSFORMATIONS. 

heritage  for  one  of  these  tiny  insects;  but  he  con- 
fesses he  never  saw  such  contests.*  When  the 
caterpillar  has  eaten  its  way  into  the  interior  of  the 
grain,  it  feeds  on  the  farina,  taking  care  not  to  gnaw 
the  skin  nor  even  to  throw  out  its  excrements,  so  that 
except  the  little  hole,  scarcely  discernible,  the  grain 
appears  quite  sound.  When  it  has  eaten  all  the 
farina,  it  spins  itself  a  case  of  silk  within  the  now  hol- 
low grain,  and  changes  to  a  pupa  in  November. | 

Two  other  caterpillars  of  a  different  family,  the 
honeycomb  moth  (Galleria  cereana,  FABR.),  and  the 
honey  moth  (G.  alvearia,  FABR.),  the  first  having 
square,  and  the  second  rounded  wings,J  do  very 
considerable  damage  to  the  hives  of  bees.  The 
moths  of  both,  according  to  Reaumur,  appear  about 
the  end  of  June  or  beginning  of  July;  and  when  in 
danger  they  run  rather  than  fly,  gliding  with  such 
celerity  that  they  can  easily  elude  the  vigilance  of 
the  bees,  which,  indeed,  if  we  may  trust  Swam- 
merdam,  never  attack  them,  nor  prevent  their  en- 
trance into  the  hives,  unless  they  chance  to  brush 
against  them  in  their  passage.  But  Reaumur  ac- 
tually saw  the  bees  pursue  one,  though  without 
success.  It  becomes  easy  for  a  moth,  at  all  events, 
to  lay  eggs  among  the  combs;  or  as  Keys  says,  at 
the  entrance  of  the  hive:  this  writer  adds,  c  she 
spins  a  close  and  strong  web  to  defend  the  young  ;'§ 
which  is  impossible,  as  no  insect,  subsequent  to  its 
larva  state,  can  spin. 

The  caterpillar  of  the  first  species,  <  wherever  it 
passes,'  says  Swamrnerdam,  '  gnaws  round  holes 
through  the  waxen  cells,  one  caterpillar  sometimes 
breaking  open  and  destroying  fifty  or  sixty  eel-Is, 

*  See  Insect  Architecture,  p.  231. 

+  R>  aumur,  Mem.,  vol.  ii,  p.  486,  &c. 

$  Stephens's  Catalogue,  vol.  ii,  p.  213. 

§  Keys,  Treatise  on  Bees,  p.  178,  edit.  1814, 


RAVAGES    OF    CATERPILLARS. 


223 


Wherever  it  penetrates  it  always  fabricates  a  hollow 
tubulated  web,  in  which,  as  a  rabbit  in  its  burrow, 
it  can  very  swiftly  pass  from  one  part  to  another, 
and  speedily  run  back  again.  It  fills  the  whole 
comb  with  such  webs,  and  turns  itself  in  them 
every  way  into  various  bendings  and  windings;  so 
that  the  bees  are  not  only  perplexed  and  disturbed  in 
their  work,  but  they  frequently  entangle  themselves 
by  the  claws  and  hairs  of  their  legs  in  those  webs,  and 
the  whole  hive  is  destroyed.' 

The  other  species  he  accuses  of  being  not  only 
destructive  to  the  wax,  but  to  the  bees  themselves. 
*  I  saw  one  of  these  little  caterpillars,'  he  says, 
i  whilst  it  was  still  small,  and  was  breaking  the  cells 
in  which  the  pupa  of  the  bees  lie,  and  eating  the  wax 


Transformations  of  the  honeycomb  moths,  a,  «,  «,  a,  Galleries  of 
the  cell-boring  caterpillar  ;  6," the  female  :  c,  the  male  moth  (Gal- 
leria  alvearia) ;  d,  rf,  <?,  d,  galleries  of  the  wax-eating  cater- 
pillar, e,  seen  at  the  entrance ;  /,  the  same  exposed  ;  g-,  its 
cocoon ;  A,  the  moth  (ChtUena  cereana). 


224  INSECT    TRANSFORMATIONS 

there,  cover  up  these  pupae  with  its  excrements,  so 
that  they  could  scarcely  be  known.'  He  adds  with 
great  na'ivett',  '  I  have  learned  these  matters  much 
against  my  inclination,  and  have  been  full  of  wrath 
against  the  insect  for  thus  defiling  and  killing  some 
bee  pupas  which  I  had  designed  to  observe  in  their 
changes.'* 

M.  Bazin,  a  friend  of  Reaumur's,  discovered  the 
caterpillar  of  a  moth  of  this  order  feeding  on  choco- 
late, of  which  it  seemed  very  choice,  always  pre- 
ferring that  which  had  the  finest  flavour.  The  moth 
is  sometimes  produced  in  September,  and  some- 
times in  the  beginning  of  the  following  summer. 
It  is  probable  that,  like  the  cheese-fly,  it  might,  in 
default  of  chocolate,  select  some  other  aliment. "f 

*  Swammerdam,  vol.  i,  p.  225.     t  Reaumur,  vol.  iii,  p.  277. 


CHAPTER  IX. 

Voracity  of  Caterpillars,  Grubs,  and  Maggots  5  —  continued. 

GRUBS. 

WE  frequently  hear  farmers  and  gardeners  com- 
plaining that  their  produce  is  destroyed  by  c  the 
grub;'  they  might  with  equal  propriety  accuse 
c  the  bird'  when  their  ripe  seeds  are  devoured 
by  sparrows,  chaffinches,  linnets,  and  other  seed- 
eaters.  Instead  of  one  sort  of  grub,  as  the  expression 
seems  to  indicate,  we  are  far  under  the  mark  in 
reckoning  a  thousand  species  indigenous  to  Britain, 
each  peculiar  in  its  food  and  its  manners.  We  shall, 
however,  adhere  as  nearly  as  possible  to  the  terms  in 
common  use;  but  as  the  larvae  of  the  crane-flies 
(Tipulidce,  LEACH),  being  without  legs,  cannot  be 
accurately  ranked  with  the  legged  grubs  of  beetles, 
we  shall  consider  them  as  maggots,  though  they  are 
usually  termed  grubs  by  the  farmers. 

The  most  destructive,  perhaps,  of  the  creatures 
usually  called  grubs,  are  the  larvae  of  the  may-bug 
or  cockchafer  (-Melolontha  vulgaris),  but  too  well 
known,  particularly  in  the  southern  and  midland 
districts  of  England,  as  well  as  in  Ireland,  where 
the  grub  is  called  the  Connaught  worm;*  but  fortu- 
nately not  abundant  in  the  north.  We  only  once 
met  with  the  cockchafer  in  Scotland,  at  Sorn,  in  Ayr- 
shire.|  Even  in  the  perfect  state,  this  insect  is  not 
a  little  destructive  to  the  leaves  of  both  forest  and 
fruit  trees.  In  1823,  we  remember  to  have  observed 
almost  all  the  trees  about  Dulwich  and  Camberwell 

*  Bingley,  Anim.  Biog.  vol.  iii,  p.  230.  t  J.  R. 


226  INSECT    TRANSFORMATIONS. 

defoliated  by  them;  and  Salisbury  says,  the  leaves  of 
the  oaks  in  Richmond  Park  were  so  eaten  by  them, 
that  scarcely  an  entire  leaf  was  left.  But  it  is  in  their 
previous  larva  state  that  they  are  most  destructive,  as 
we  shall  see  by  tracing  their  history. 

The  mother  cockchafer,  when  about  to  lay  her  eggs, 
digs  into  the  earth  of  a  meadow  or  corn-field  to  the 
depth  of  a  span,  and  deposits  them  in  a  cluster  at  the 
bottom  of  the  excavation.  Rosel,  in  order  to  watch 
their  proceedings,  put  some  females  into  glasses  half- 
filled  with  earth,  covered  with  a  tuft  of  grass,  and  a 
piece  of  thin  muslin.  In  a  fortnight,  he  found  some 
hundreds  of  eggs  deposited,  of  an  oval  shape  and  a 
pale  yellow  colour.  Placing  the  glass  in  a  cellar,  the 
eggs  were  hatched  towards  autumn,  and  the  grubs  in- 
creased remarkably  in  size.  In  the  following  May 
they  fed  so  voraciously  that  they  required  a  fresh  turf 
every  second  day;  and  even  this  proving  too  scanty 
provender,  he  sowed  in  several  garden  pots  a  crop  of 
peas,  lentils,  and  salad,  and  when  the  plants  came  up, 
he  put  a  pair  of  grubs  in  each  pot;  and  in  this  man- 
ner .  he  fed  them  through  the  second  and  third  years. 
During  this  period,  they  cast  their  skins  three  or  four 
times,  going  for  this  purpose  deeper  into  the  earth, 
and  burrowing  out  a  hole  where  they  might  effect 
their  change  undisturbed;  and  they  do  the  same  in 
winter,  during  which  they  become  torpid  and  do  not 
eat. 

When  the  grub  changes  into  a  pupa,  in  the  third 
autumn  after  it  is  hatched,  it  digs  a  similar  burrow 
about  a  yard  deep;  and  when  kept  in  a  pot,  and  pre- 
vented from  going  deep  enough,  it  shows  great  un- 
easiness and  often  dies.  The  perfect  beetle  comes 
forth  from  the  pupa  in  January  or  February;  but  it  is 
then  as  soft  as  it  was  whilst  still  a  grub,  and  does 
not  acquire  its  hardness  and  colour  for  ten  or  twelve 
days,  nor  does  it  venture  above  ground  before  May, 


RAVAGES    OF    GRUBS. 


227 


on  the  fourth  year  from  the  time  of  its  hatching.  At 
this  time,  the  beetles  may  be  observed  issuing  from 
their  holes  in  the  evening,  and  dashing  themselves 
about  in  the  air  as  if  blind. 


Transformations  of  the  cockchafer  (Mt/olontha  -vulgaris).  a, 
newly  hatched  larvae.  6,  larva,  one  year  old.  c,  the  same  larva 
at  the  second  year  of  its  growth,  d,  the  same  three  years  old.  e, 
section  of  a  bank  of  earth,  containing  the  chrysalis  of  the  fourth 
year.  /,  the  chafer  first  emerging  from  the  earth,  g-,  the  perfect 
chafer  in  a  sitting  posture.  A,  the  same  flying. 

During  the  three  summers  then  of  their  existence 
in  the  grub  state,  these  insects  do  immense  injury, 
burrowing  between  the  turf  and  the  soil,  and  devour- 
ing the  roots  of  grass  and  other  plants;  so  that  the 


228  INSECT    TRANSFORMATIONS. 

turf  may  be  easily  rolled  off,  as  if  cut  by  a  turfing 
spade,  while  the  soil  underneath  for  an  inch  or  more 
is  turned  into  soft  mould  like  the  bed  of  a  garden, 
Mr  Anderson,  of  Norwich,  mentions  having  seen 
a  whole  field  of  fine  flourishing  grass  so  under- 
mined by  these  grubs,  that  in  a  few  weeks  it  became 
as  dry,  brittle,  and  withered  as  hay.*  Bingley  also 
tells  us  that  £  about  sixty  years  ago,  a  farm  near 
Norwich  was  so  infested  with  cockchafers,  that  the 
farmer  and  his  servants  affirmed  they  gathered  eighty 
bushels  of  them;  and  the  grubs  had  done  so  much 
injury,  that  the  court  of  the  city,  in  compassion  to 
the  poor  fellow's  misfortune,  allowed  him  twenty  - 
five  pounds. 'I  In  the  year  1785,  a  farmer,  near 
Blois,  in  France,  employed  ar  number  of  children  and 
poor  persons  to  destroy  the  cockchafers  at  the  rate 
of  two  liards  a  hundred,  and  in  a  few  days  they  collect- 
ed fourteen  thousand. J 

'  I  remember,'  says  Salisbury,  c  seeing,  in  a  nur- 
sery near  Bagshot,  several  acres  of  young  forest 
trees,  particularly  larch,  the  roots  of  which  were  com- 
pletely destroyed  by  it,  so  much  so,  that  not  a  single 
tree  was  left  alive. '§  We  are  doubtful,  however, 
whether  this  was  the  grub  of  the  cockchafer,  and 
think  it  more  likely  to  have  been  that  of  the  green 
rose  beetle  (Cetonia  aurata),  which  feeds  on  the 
roots  of  trees. 

The  grub  of  an  allied  genus,  the  midsummer 
chafer  (Zantheumia  Solstilialis,  LEACH),  has  for  the 
last  two  years  been  abundant  on  Lewisham  Hill, 
Blackheath,  doing  considerable  injury  to  herbage 
and  garden  plants.  This  beetle  may  be  known  from 
being  smaller  and  paler  than  the  cockchafer,  and 
from  its  not  appearing  before  midsummer.  The  grub 
is  very  similar. 

*  Philosoph.  Trans,  xliv,  579.  t  Aniiru  Biog.  iii,  233. 

$  Anderson's  Recr.  in  Agricult.  iii,  420.  §  Hints,  74. 


RAVAGES    OF    GRUBS.  229 

The  best  way  of  preventing  the  ravages  of  these 
insects  would  be  to  employ  children  to  collect  the 
perfect  insects  when  they  first  appear,  before  they  lay 
their  eggs;  but  when  a  field  is  once  overrun  with 
the  larva,  nothing  can  be  done  with  it,  except  paring 
and  burning  the  surface,  or  ploughing  it  up,  and 
turning  in  a  flock  of  ducks  or  other  poultry,  or  a 
drove  of  pigs,  which  are  said  to  eat  these  grubs, 
and  to  fatten  on  the  fare.  Drenching  the  field  with 
stable  urine*  by  means  of  reservoir  carts,  like  those 
used  for  watering  roads,  would,  if  sufficiently  done, 
both  kill  the  grubs,  and  beneficially  manure  the  land. 

The  grub  called  the  wire  worm,  though  not  very 
appropriately,  is  the  larva  of  one  of  the  spring  or 
click  beetles  (Hemirhipus  lineatus,  and  H.  obscurus, 
LATREILLE),  known  by  their  long  flattish  body,  and 
their  power  of  springing  with  a  clicking  sound  out 
of  the  hand  when  caught.  In  some  works  on  agri- 
culture, the  larva  of  a  common  crane  fly  (Tipula 
oleracea  or  T.  crocata)  is  called  the  wire  worm,  —  we 
suppose  by  mistake. "\  The  grubs  of  the  click  bee- 
tles, just  alluded  to,  are  said  by  Bierscander  J  and 
by  Mr  Paul  of  Starston,  Norfolk  ,§  who  watched 
their  transformations,  to  continue  five  years  before 
producing  the  perfect  insect.  During  this  time  the 
grub  feeds  chiefly  on  the  roots  of  wheat,  rye,  oats, 
barley,  and  grass;  but  seems  also  sometimes  to  attack 
the  larger  roots  of  potatoes,  carrots,  and  salads.  Its 
ravages  are  often  so  extensive  as  to  cut  off  entire 
crops  of  grain.  It  appears  to  be  most  partial  to  land 
newly  broken  up;  and  has  not  been  found  so  abun- 
dant in  meadows  and  pastures,  unless  in  fields  recently 
laid  down  with  grass.  '  The  wire  worm,'  says 
Spence,  c  is  particularly  destructive  for  a  few  years 

*  See  the  Harleian  Dairy  System,  p.  222. 
t  See  Loudon's  Encycl.  of  Agricult.  §    6921. 
J  Act.  Holm.  1779,  p.  284.         §  Kirby  and  Spence,  i,  182. 
TOL.  vi.  20 


230 


INSECT    TRANSFORMATIONS. 


in  gardens  recently  converted  from  pasture  ground. 
In  the  botanic  garden  at  Hull,  thus  circumstanced,  a 
great  proportion  of  the  annuals  sown  in  1813  were 
destroyed  by  it.  A  very  simple  and  effectual  remedy, 
in  such  cases,  was  mentioned  to  me  by  Sir  Joseph 
Banks.  He  recommended  that  slices  of  potatoes 
stuck  upon  skewers,  should  be  buried  near  the  seeds 
sown,  examined  every  day,  and  the  wire- worms, 
which  collect  upon  them  in  great  numbers,  de- 
troy  ed.'* 

The  wire  worm  is  long,  slender,  and  very  tough 
and  hard  ;  but  otherwise  it  has  no  resemblance  to 
wire,  being  whitish  in  colour,  of  a  flattish  form,  and 
jointed  or  ringed.  Its  breathing  spiracles,  two  in 
number,  are  on  the  back  of  its  last  ring. 


a,  Wire  worm ;  6,  Click  beetle. 

An  insect  of  this  family  (Elater  noctilucus,  LINN.) 
is  exceedingly  destructive,  in  the  West  Indies,  to  the 
sugar-cane;  the  grub,  according  to  Humboldt  and 
Bonpland,  feeding  on  its  roots  and  killing  the 
plants."]* 

Instances  are  by  no  means  rare,  however,  of  in- 
sects being  accused  of  depredations  of  which  they  are 
not  guilty,  from  the  mere  circumstance  of  their  being 

*  Intr.  i,  182-3.          t  Geog.  des  Plantes,  136. 


RAVAGES    OF    GRUBS.  231 

found  in  abundance  where  ravages  have  been  com- 
mitted by  others  that  have  naturally  disappeared  It 
is  not  improbable  that  this  was  the  case  with  a  grub 
of  some  beetle  (Staphylinidce!),  mentioned  by 
Mr  Walford,  and  mistaken  by  him  for  the  wire 
worm  Out  of  fifty  acres  of  wheat  sown  in  1802, 
ten  had  been  destroyed  in  October,  by  this  grub 
eating  into  the  centre  of  the  young  stem  an  inch 
below  the  surface  and  killing  the  plant.*  It  seems 
still  more  probable  that  the  grub  of  a  native  beetle 
(Zabrus  gibbus,  STEPHENS),  which  has  been  found 
in  considerable  numbers  near  Worthing,  Brighton, 
Hastings,  and  Cambridge,  has  been  unjustly  blamed 
as  a  destroyer  of  corn;  though  we  have  the  respect- 
able authority  of  Germar,  who,  with  other  members 
of  the  society  of  Natural  History  of  Halle,  ima- 
gined he  had  ascertained  the  fact.  In  the  spring  of 
1813,  about  two  hundred  and  thirty  acres  of  young 
wheat  are  said  to  have  been  destroyed  by  it;  and  it 
is  farther  supposed  to  be  the  same  insect  which 
caused  great  destruction  in  Italy  in  1776.  This  grub 
is  said  to  take  probably  three  years  in  coming  to  a 
beetle,  in  which  state  it  is  alleged  to  clamber  up  the 
stems  at  night,  to  get  at  the  corn.  It  is  important 
to  remark,  that  along  with  these  grubs  were  found 


x 

a,  Zabrus  glbbus  ;  6,  Melolontha  ruficornis. 
*  Linn.  Trans,  ix,  156-61. 


INSECT    TRANSFORMATIONS. 

those  of  a  chafer  (Melolontha  ruficornis,  FABR.),  in 
the  proportion  of  about  a  fourth.* 

To  this  account,  Mr  Stephens  appends  the  shrewd 
questions  — '  May  not  these  herbivorous  larva?  [of  the 
chafer]  have  been  the  principal  cause  of  mischief  to 
the  wheat,  while  those  of  the  Zabrus  rather  contri- 
buted to  lessen  their  numbers,  than  to  destroy  the 
corn  ?  And  is  it  not  probable  that  the  perfect  insects 
ascend  the  corn  for  the  purpose  of  devouring  the 
insect  parasites  thereon?  This  is  a  subject,'  he 
justly  adds,  '  that  requires  investigation,  as  it  is  high- 
ly important,  for  the  interests  of  the  agriculturist 
in  those  districts  where  the  insect  abounds,  that 
the  question  should  be  thoroughly  set  at  rest;  be- 
cause, should  the  Zabri  depart  from  the  habits  of 
the  group  to  which  they  belong,  and  become  herbi- 
vorous instead  of  carnivorous,  their  destruction  would 
be  desirable  ;  while,  on  the  contrary,  if  they  destroy 
the  devourers  of  our  produce  their  preservation  should 
be  attempted.'')" 

We  have  little  doubt  that  Mr  Stephens  is  right, 
and  Gerrnar  wrong  ;  but  it  would  be  improper  to 
decide  the  question  by  analogy  unsupported  by  direct 
experiment.  One  thing  is  certain,  that  both  this 
family  (Harpalidce,  MACLEAY)  and  the  whole  sec- 
tion (Mephaga,  CLAIRVILLE)  are  riot  herbivorous, 
but  carnivorous.J  Similar  errors  will  corne  under 
our  notice,  as  we  proceed,  not  more  defensible 
than  that  of  the  old  soldier  causing  caterpillars  in 
France.^ 

Even  when  agricultural  produce  escapes  being 
devoured  at  the  root,  or  the  young  shoots  eaten  up, 
the  seeds  are  often  made  the  prey  of  the  grubs  of 

*  Germar,  Mag.  der  Entomol.,  i,  1-10  ;  and  Kirby  and 
Spence  i,  169. 

t  Stephens,  Illustrations,  i,  Mandib.  pp.  4  and  140. 
$  See  an  Illustration  in  Insect  Architect.,  p.  207-8. 


RAVAGES   OF    GRUBS.  233 

beetles  and  weevils.  Among  the  first,  the  gnawing 
beetles  (Bruchidcc,  LEACH)  are  very  destructive. 
In  North  America,  the  pea  beetle  (Bruchus  Pisi, 
LINN.)  commits  such  extensive  depredations  on 
pulse,  that  in  some  districts  the  sowing  of  peas  has 
been  abandoned  as  useless.  Kalm,  the  Swedish 
traveller,  having  witnessed  these  depredations  in 
America,  became  quite  alarmed  when  he  discovered 
the  insect  among  some  peas  he  had  brought  to 
Sweden,  lest  he  should  be  the  means  of  introducing 
so  formidable  a  pest.^  His  fears  seem  to  us  to  have 
been  in  a  great  measure  groundless  ;  for,  probably, 
the  insect  may  be  indigenous  to  Sweden,  as  it  is  to 
Britain,  though  from  circumstances  of  climate,  and 
other  causes,  it  is  seldom  produced  in  such  numbers 
with  us  as  to  occasion  extensive  damage.  It  may  have 
been  the  same  or  an  allied  species  of  grub  mentioned 
by  Amoroux  as  having  spread  an  alarm  in  France  in 
1780,  when  the  old  fancy  of  its  being  poisonous 
induced  the  public  authorities  to  prohibit  peas  from 
being  sold  in  the  markets. |  The  insect  most 
destructive  to  our  peas  is  the  pulse  beetle  (Bruchus 
granariuSy  LINN.),  which  sometimes  lays  an  egg  on 
every  pea  in  a  pod,  which  the  grub,  when  hatched, 
destroys.  In  the  same  way>  clover  seed  is  often  attacked 
by  two  or  more  species  of  small  weevil  (Jlpion, 
HERBST),  known  by  the  yellow  colour  of  their 
thighs  or  their  feet;  and  when  the  farmer  expects  to 
reap  considerable  profit,  he  finds  nothing  but  empty 
husks. 

We  have  mentioned  the  ravages  committed  in 
granaries  by  the  caterpillars  of  small  moths  ;  but 
these  are  rivalled  in  the  work  of  destruction  by 
several  species  of  grubs.  One  of  these  grubs  is 

*  Kalm's  Travels,  vol.  i,  p.  173. 

t  Amoroux,  Insectes  Venimeux,  288.  Kirby  and  Spence, 
i,  177. 

VOL.    VI.  20* 


234  INSECT    TRANSFORMATIONS. 

called  by  the  French  cadelle  ( Trogosita  mauritamca, 
OLIVIER),  and  is  reported  to  have  done  more  damage 
to  housed  grain  than  any  other  insect.*  The  pest 
of  the  granaries,  which  is  but  too  well  known  in  this 
country,  is  the  grain  weevil  (Calandra  granaria, 
CLAIRVILLE),  the  same,  probably,  which  is  mentioned 
by  Virgil, 

Populatque  ingentem  farris  acervum 

Curculio.  Georg.  i,  87. 

The  high  stacks  of  corn 

Are  wasted  by  the  weevil.  Trapp . 

Kirby  and   Spence  calculate  that  a  single  pair  of 
weevils  may  produce  in  one  season  6000  descendants; 
and  they  were  told  by  an  extensive  brewer  that  he 
had   collected    and  destroyed   them   by   bushels,"!"  — 
meaning,  no  doubt,  insects  and  damaged  grain  to 
gether. 


Corn  weevil  (Calandra  grunaria),  magnified. 

Another  beetle  grub,  popularly  called  the  meal 
worm,  the  larva  of  Tenebrio  molitor,  LINN.,  which 
lives  in  that  state  two  years,  does  no  little  damage  to 
flour,  as  well  as  to  bread,  cakes,  biscuit,  and  similar 
articles.  Accounts  are  also  given  of  the  ravages  com- 
mitted by  the  grubs  of  other  beetles,  of  several  species 
apparently  not  well  ascertained,  upon  different  sorts  of 
provisions,  such  as  bacon,  ham,  dried  tongues,  ship 
biscuit,  &c.  Sparrman  tells  us,  that  he  has  wit- 
nessed the  ground  peas  on  ship-board  so  infested 

*  Olivier,  ii,  19.  t  Intr.  i,  173. 


RAVAGES    OF    GRUBS,  235 

with  these  grubs,  that  they  were  seen  in  every 
spoonful  of  the  soup.  In  the  case  of  soup,  or  of  other 
food  which  has  been  exposed  to  heat,  the  only 
inconvenience  is  the  disgust  which  must  ensue; 
but,  unfortunately,  there  may  sometimes  occur  cir- 
cumstances of  a  more  serious  nature,  — -  from  either 
the  eggs  or  the  insects  themselves  being  incautiously 
swallowed  alive.  We  do  not  wish,  however,  to 
create,  so  much  as  to  allay,  the  fears  entertained  by 
those  who  are  unacquainted  with  the  habits  of 
insects;  and  nothing  we  are  persuaded  will  do  this 
more  effectually  than  a  statement  of  facts  well 
ascertained.  c  Several  people/  says  the  Abbe  de  la 
Pluche,  '  never  eat  fruit  because  they  believe  that 
spiders  and  other  insects  scatter  their  eggs  upon  it 
at  random;'*  but  even  if  this  were  so,  as  it  is  not, 
it.  would  be  impossible  for  the  young,  should  they  be 
hatched  in  the  stomach,  to  live  there  for  an  instant. 
The  possible  cases  in  which  this  may  occur  we  shall 
now  briefly  notice;  they  are  fortunately  very  rare. 

The  meal  worm,  and  some  of  the  grubs  which 
feed  on  grain  and  other  provisions,  are  recorded  to 
have  been  swallowed,  and  to  have  given  rise  to 
disorders  in  the  stomach  and  bowels ;  but  in  all  such 
cases  it  is  plain,  that  if  the  insects  did  survive 
the  increased  temperature  of  the  stomach,  they 
could  only  live  on  the  food  swallowed  from  time  to 
time,  for,  not  being  carnivorous,  they  would  not  attack 


Meal  worm,  and  the  beetle  produced  from  it. 
*  Spectacle  de  la  Nature,  i,  65. 


236 


INSECT    TRANSFORMATIONS. 


the  stomach  itself.  The  same  remark  will  apply  no 
less  forcibly  to  the  herbivorous  larvae,  which  might 
chance  to  be  swallowed  in  salad,  &c.  The  cater- 
pillar of  the  tabby  moth  (Jlglossa  pinguinalis, 
LATREILLE),  which  feeds  on  butter,  the  leather  on 
book-boards,  &c,  is  said,  on  the  authority  of  Lin- 
naeus, to  get  sometimes  into  the  stomach,  and  to 
produce  considerable  disorder;*  but  this  insect  is 
very  common  in  houses,")"  and,  from  the  rarity  of 
such  accidents,  we  are  led  to  doubt  the  evidence 
usually  brought  forward.  In  this  case  we  are 
the  more  induced  to  question  the  authority  of  Lin- 
naeus, from  his  having  made  an  evident  mistake  in  a 
similar  case  respecting  intestinal  worms. 


Transformations  of  the  tabby  moth  (A^lossapinguin':lis).  a,  the 
caterpillar  feeding  on  butter  ;  6,  c,  d,  feeding  on  leather  under 
galleriefe  :  e,  the  moth  with  the  down  rubbed  off  ;  /,  the  same 
perfect. 

Linnaeus  affirms,  that  in  the  presence  of  seven  of 
his  companions  he  discovered,  near  Reuterholm,  in 
Dalecarlia,  a  tape  worm  in  acidulous  ochre  (  Ockram 
at  which  he  marvelled  the  more  since 


*  Linnaeus,  quoted  by  Kirby  and  Spence,  i,  136. 
t  Latreille,  Hist.  Geprrale,  xiv,  229. 


INTESTINAL     WORMS.  237 

acidulous  water  of  this  kind  had  been  drank  with 
the  design  of  expelling  these  worms. *  This 
account,  however,  proves  too  little;  for,  as  Bonnet, 
Reaumur,  Pallas,  and  other  eminent  naturalists 
remark,  if  such  were  the  fact,  we  should  find  in- 
testinal worms  (so  very  numerous  in  most  animals) 
swarming  in  such  places,  and  from  their  size 
(Boerhaave  saw  one  thirty-  ells  long)  they  could 
not  escape  observation;  whereas  this  was  at  that 
time  the  only  instance  recorded  of  one  found 
out  of  the  body.  We  are  of  opinion  that  Lin- 
naeus must  have  been  deceived  by  similarity  of 
form.  A  subsequent  instance  is  recorded  by  Dr 
Barry,  of  Cork,  who  imagined  he  had  found  the 
origin  of  the  common  small  thread  worm  (Oxyuris 
vermicularis,  BREMSER)  in  the  water  of  a  well  —  the 
aquatic  only  differing  from  the  intestinal  worms 
in  colour.  But  were  all  descriptions  as  loose  as  this 
the  grossest  mistakes  must  ensue;  for  it  is  quite 
clear  that  Dr  Barry's  aquatic  worms  were  a  very 
common  species  (JVais\  and  though  similar  in 
external  form,  altogether  different  in  internal 
structure  from  the  Oxyuridce  of  the  intestines. 
Were  the  latter,  indeed,  introduced  into  the  body 
from  water,  they  would  not  only  be  found  in  this 
particular  well,  two  miles  from  Cork,  but  would 
swarm  in  all  the  waters  in  the  empire;  since  there 
are  few  individuals  who  are  not  affected  with  these 
worms  at  some  period  of  their  lives.  According  to 
our  experiments,  the  nai's  ceases  to  exist  in  a  tem- 
perature considerably  less  than  that  of  the  human  bo- 
dy; besides,  as  it  lives  on  minute  fresh-water  mollus- 
cse,  it  could  find  no  food  in  the  intestines. t 

The  celebrated  Dr  J.  P.  Frank  is  no  less  mistaken 
in  referring  us  for  the  origin  of  intestinal  worms  to 
f  minute  insects  flying  in  the  air;'J  for,  if  so,  the 

*  Linnaeus,  quoted  by  Bonnet,  GEuvres,  iii,  137.         t  J.R. 
£  Frank.  De  Curand.  Homin.  Morb.  lib.  vi. 


238  INSECT    TRANSFORMATIONS. 

worms  would  naturally  produce  similar  insects  to 
their  parents;  whereas  they  are  either  oviparous,  as 
Goetze  affirms,  or,  as  Bremser  thinks,  ovo-viparous;^ 
both  agreeing  that  they  are  not  transformed  into 
flying  insects.  Reaumur  made  the  more  plausible 
conjecture,  that  they  might  be  introduced  by  eating 
tench  and  other  fish,  in  which  they  are  known  to 
abound;|  but,  independently  of  their  being  destroyed 
by  heat  in  cooking,  this  has  been  subsequently  dis- 
proved by  experiment;  for  M.  Deslonchamps  says, 
that  'when  animals  are  fed  for  some  time  on  in- 
testinal worms  (Entoozaria)  alone,  and  then  killed, 
they  are  not  found  infested  with  these  worms. 'J 
Valisnieri  and  Hartsocker  suppose,  without  a  shadow 
of  proof,  that  worms  are  transmitted  from  parents 
to  children  like  other  hereditary  disorders;  while 
the  late  M.  Lamarck  refers  their  production  to  c  the 
march  of  nature  in  the  production  of  all  living 
beings  !'§  This  indefinite  doctrine  is  also  held  by 
Geoffroi  St  Hilaire,  Cuvier,  Blumenbach,  and  other 
distinguished  living  naturalists;  but  we  think  it  more 
philosophical  and  more  manly,  in  such  obscure  cases, 
at  once  to  confess  our  ignorance  of  the  ways  of  nature, 
and  to  wait  for  further  observation,  than  to  frame  idle 
theories,  supported  only  by  vague  analogies  and  doubt- 
ful facts. 

It  may  not  be  uninteresting  to  mention,  however, 
that  upwards  of  1200  species  of  intestinal  worms 
have  been  discovered;  and  probably  there  may  be 
twice  as  many  more  of  whose  existence  nothing  is 
yet  known.  Sixteen  of  these  species  have  been 
found  in  the  human  body ;  the  rest  are  peculiar  to 
other  animals.  ||  Some  of  the  more  singular  species. 

*  Bremser,  Uber  Lebende  Wb'rmer  in  leb.  Mensch, 
t  Letter  to  Bonnet,  OEuvres,  vol.  iii,  p.  344. 
J  Diet.  Classique,  vol.  viii,  p.  589- 
$  Anim.  sans  Vertebres,  vol.  i,  p.  15. 
II  Diet.  Classique,  vol.  viii,  p.  593. 


INTESTINAL    WORMS. 


239 


are   here    represented,    from  the    splendid    work   of 
Bremser. 


Intestinal  worms. 

That  insects  are,  in  some  rare  cases,  intro- 
duced into  the  human  stomach,  has  been  more  than 
once  proved  ;  though  the  greater  number  of  the 
accounts  of  such  facts  in  medical  books  are  too 
inaccurate  to  be  trusted.*  But  one  extraordinary 
case  has  been  completely  authenticated,  both  by  me- 
dical men  and  competent  naturalists;  and  is  pub- 
lished in  the  Dublin  Transactions,  by  Dr  Pickells 
of  Cork. |  Mary  Riordan,  aged  28,  had  been  much 
affected  by  the  death  of  her  mother,  and  at  one  of 
her  many  visits  to  the  grave  seems  to  have  partially 
lost  her  senses,  having  been  found  lying  there  on 
the  morning  of  a  winter's  day,  and  having  been  ex- 
posed to  heavy  rain  during  the  night.  When  she 
was  about  fifteen,  two  popular  Catholic  priests  had 
died,  and  she  was  told  by  some  old  women  that  if  she 

*  See  Good's  Nosologia,  Helminthia  Alvi;  and  Study  of  Med. 
vol.  i,  p.  336 

t  Trans,  of  Assoc.  Phys.  in  Ireland,  iv,  vii,  and  v.,  p.  177, 
8vo.  Dublin,  1824  —  1828. 


240  INSECT    TRANSFORMATIONS. 

would  drink  daily,  for  a  certain  time,  a  quantity  of 
water,  mixed  with  clay  taken  from  their  graves,  she 
would  be  for  ever  secure  from  disease  and  sin.  Fol- 
lowing this  absurd  and  disgusting  prescription,  she 
took  from  time  to  time  large  quantities  of  the  draught ; 
some  time  afterwards,  being  affected  with  a  burning 
pain  in  the  stomach  (Cardialgia),  she  began  to  eat 
large  pieces  of  chalk,  which  she  sometimes  also  mixed 
with  water  and  drank. 

Now,  whether  in  any  or  in  all  of  these  draughts  she 
swallowed  the  eggs  of  insects,  cannot  be  affirmed  ; 
but  for  several  years  she  continued  to  throw  up  incre- 
dible numbers  of  grubs  and  maggots,  chiefly  of  the 
churchyard  beetle  (Blaps  mortisaga,  FABR.).  *  Of 
the  larvae  of  the  beetle,'  says  Dr  Pickells,  '  1  am 
sure  I  considerably  underrate,  when  I  say  that  not 
less  than  700  have  been  thrown  up  from  the  stomach 
at  different  times  since  the  commencement  of  my 
attendance.  A  great  proportion  were  destroyed  by 
herself  to  avoid  publicity;  many,  too,  escaped  im- 
mediately by  running  into  holes  in  the^ floor.  Up- 
wards of  ninety  were  submitted  to  Dr  Thomson's  * 
examination;  nearly  all  of  which,  including  two  of  the 
specimens  of  the  meal  worm  (Tenebrio  m-olitor),  I 
saw  myself,  thrown  up  at  different  times.  The  aver- 
age size  was  about  an  inch  and  a  half  in  length,  and 
four  lines  and  a  half  in  girth.  The  larvre  of  the  dip- 
terous insect,  though  voided  only  about  seven  or  eight 
times,  according  to  her  account ;  came  up  almost 
literally  in  myriads.  They  were  alive  and  moving.'1 
Altogether,  Dr  Pickells  saw  nearly  2000  grubs  of 
the  beetle,  and  there  were  many  which  he  did  not 
see.  Mr  Clear,  an  intelligent  entomologist  of  Cork, 
kept  some  of  them  alive  for  more  than  twelve  months. 
Mr  S.  Cooper  cannot  understand  whence  the  con- 
tinued supply  of  the  grubs  was  provided,  seeing  that 

*  The  well-known  author  of'  Zoological  Researches/  &e. 


INTESTINAL    GRUBS    AND    BEETLES.  241 

larvae  do  not  propagate,  and  that  only  one  pupa  and 
one  perfect  insect  were  voided;*  but  the  simple  fact 
that  most  beetles  live  several  years  in  the  state  of 
larvae  sufficiently  accounts  for  this.  Their  existing  and 
thriving  in  the  stomach,  too,  will  appear  less  wonder- 
ful from  the  fact  that  it  is  exceedingly  difficult  to  kill 
this  insect;  for  Mr  Henry  Baker  repeatedly  plunged 
one  into  spirit  of  wine,  so  fatal  to  most  insects,  but  it 
revived,  even  after  being  immersed  a  whole  night,  and 
afterwards  lived  three  years. "f 


Churchyard  beetle  (Blaps  mortisagct),  in  the  grub  and  perfect  state, 
from  the  figures  of  Dr  Pickells. 


That  there  was  no  deception  on  the  part  of  the 
woman,  is  proved  by  the  fact  that  she  was  always 
anxious  to  conceal  the  circumstance;  and  that  it  was 
only  by  accident  that  the  medical  gentlemen,  Drs 
Pickells,  Herrick,  and  Thomson,  discovered  it.  More- 
over, it  does  riot  appear  that,  though  poor,  she  ever 
took  advantage  of  it  to  extort  money.  It  is  interest- 

*  Cooper's  edition  of  Good's  Study  of  Medicine,  i,  358* 

Philosoph.  Trans.,  No.  457, 
VOL.   vi.  2! 


242  INSECT   TRANSFORMATIONS. 

ing   to   learn    that  by  means  of  turpentine,  in  large 
doses,  she  was  at  length  cured. 

The  grub  of  the  nut  weevil  (Balaninus   Nucum, 
GERMAK)   might,   perhaps,  by  rare  accident,  get  into 
the    stomach,    either    of  man  or  of  the  quadrupeds 
which    feed    on    nuts;    but  as  it  is  by  no  means  so 
tenacious  of  life  as  the  grub  of  the  churchyard  beetle 
(Blaps   mortisaga)    above   described,    it    is  unlikely- 
that    it    would    produce    any    considerable   disorder. 
The  weevil  in  question,  like  the  rest  of  its  congeners, 
is    furnished   with    an    instrument    for    depositing  its 
eggs  considerably  different  from  those  of  the  ichneu- 
mons   and    saw-flies.       For  this  purpose  the  weevil 
makes  use  of  its  long  horny  beak  (Rostrum)  to  drill 
a  hole  in  filberts  and  hazel  nuts,  while  in  their  young 
and  soft  state,  about  the  beginning  of  August.     The 
mother    weevil    may  then   be   seen  eagerly  running 
over  the  bushes,  and  it  would  appear  that  she  always 
rejects  the  nuts  in  which  one  of  her  neighbours  may 
have  previously  laid  an  egg;  at  least  we  never  .find 
two  grubs  in  the  same  nut.     The  egg,  which  is  thus 
thrust  into  the  young  nut,  is  of  a  brown  colour,  and 
is  hatched  in  about  a  fortnight,  the  grub  feeding  on 
the  interior  of  the  shell  as  well  as  the  soft  pulp,  till 
the  one  becomes  too  hard  and  the  other  too  dry  to  be 
nutritive.     It  is  remarkable  that,  during  this  period, 
he  takes  care  not  to  injure  the  kernel,  but  permits  it 
to  ripen  before  he  attacks  it.     Had  he  done  this  pre- 
maturely, he  would  have  ultimately  been  starved,  as 
he   has    not    the    power    of  perforating  another  nut 
when  the  first  is  consumed.     It  is  said  also  that  he 
is  very  careful  to  preserve  the  original  hole  made  by 
the  mother,  by  gnawing  around  its  inner  edges,  in 
order  to  facilitate  his  exit/  which  he  effects  when  the 

*  Bingley,  Animal  Biography,  vol.  viii,  p.  251. 


GRUBS   OF    WEEVILS. 


243 


nut  falls  to  the  ground  in  September  or  October. 
The  hole  found  in  the  nut  appears  much  too  small 
to  have  admitted  of  its  passage ;  but  from  being  very 
soft  it  no  doubt  stretches  itself  out  for  the  purpose, 
usinp;  its  short  claws  as  instruments  of  motion. 

Rosel,  in  order  to  observe  the  transformation  of 
these  nut  grubs,  put  a  number  of  them,  at  the  com- 
mencement of  winter,  into  glasses  half  filled  with 
earth,  covered  with  green  turf.  All  of  them  dug 
directly  down  into  the  earth,  remained  there  all 
the  winter,  and  did  not  change  into  pupae  till  the  fol- 
lowing June ;  the  perfect  weevils  appeared  from  the 
1st  till  about  the  20th  of  August,  but  still  kept  under 
ground  for  the  first  week  after  their  change. 


Nut  and  apple-tree  beetles.  A,  a  branch  of  the  filbert-tree 
a,  egg  hole  in  the  nut ;  6,  exit  hole  of  the  grub.  B,  the  larvse  of 
the  nut  beetle.  C,  the  same  in  the  pupa  btate.  D,  female  beetle. 
E,  male  beetle,  c,  the  beetle  that  destroys  the  bloom-bud  of  the 
apple  tree-,  a,  the  same  in  the  larva  state;  6,  the  chrysalis  of 
the  same. 

c  During  the  autumn,'  says  Salisbury,  '  we  fre- 
quently observe  a  small  red  weevil  busily  employed 
in  traversing  the  branches  of  apple-trees,  on  which 
it  lays  its  eggs  by  perforating  the  bloom  buds.  In 
the  spring,  these  hatch,  and  the  grubs  feed  on  the 


244  INSECT    TRANSFORMATIONS. 

petals  of  the  flowers,  drawing  up  the  whole  flower 
into  a  cluster  by  means  of  their  web.  The  bloom 
thus  becomes  destroyed,  and  the  grub  falls  to  the 
ground,  where  it  lays  itself  up  in  the  chrysalide  state ; 
and  in  the  autumn  afterwards  we  find  the  weevil 
renewed,  which  again  perforates  the  buds,  and  causes 
a  similar  destruction  in  the  following  spring.  Mr 
Knight,  in  his  treatise  on  the  apple,  mentions  a  beetle 
which  commits  great  destruction  on  the  apple-trees  in 
Herefordshire;  but  I  do  not  think  it  the  same  as  the 
one  I  have  described  above,  and  which  is  very  common 
in  the  gardens  near  London.'*  Salisbury's  weevil 
is  probably  the  Jlnthonomus  Pomorum  of  Germar; 
and  Knight's,  his  Poiydrusus  Mali.  Another  weevil 
(Rhijnchites  Bacchus,  HERBST),  one  of  our  most 
splendid  but  not  very  common  native  insects,  bores 
into  the  stone  of  the  cherry,  &c,  while  it  is  young 
and  soft,  and  deposits  an  egg  there,  as  the  nut  weevil 
does  in  the  nut. 

*  Perhaps  the  most  voracious  grub  on  record  is  that 
of  a  large  and  beautiful  beetle  (Calosoma  syco- 
phanta,  WEBER),  which  is  rare  in  Britain.  It  is 
sometimes  found  in  the  nests  of  the  processionary  and 
other  gregarious  caterpillars,  so  gorged  with  those  it 
has  devoured  that  it  can  scarcely  move  without 
bursting.  JN"ot  contented  with  this  prey  alone,  how- 
ever, the  younger  grubs  are  said  c  often  to  take  ad- 
vantage of  the  helpless  inactivity  into  which  the  glut- 
tony of  their  maturer  comrades  has  thrown  them, 
and  from  mere  wantonness,  it  should  seem,  when  in 
no  need  of  other  food,  pierce  and  devour  them.'f  It 
is  a  familiar  occurrence  to  those  who  breed  insects  to 
find  caterpillars,  whose  natural  food  is  leaves,  devour- 
ing others  in  the  same  nurse-box;  and  without  any 

*  Salisbury's  Hints  on  Orchards,  p.  92. 
t  Kirby  and  Spence,  vol.  i,  p.  277. 


GRUBS    OF    BEETLES.  245 

apparent  discrimination  whether  these  are  the  progeny 
of  their  own  mother,  or  of  a  different  species.* 

We  have  frequently  observed  a  very  remarkable 
instinct  in  the  grubs  of  a  species  of  beetle  ( Scolytus 
Destructor,  GEOFFROY),  which  lives  under  the  dead 
bark  of  trees.  The  mother  insect,  as  is  usual  with 
beetles,  deposits  her  eggs  in  a  patch  or  cluster  in  a 
chink  or  hole  in  the  bark;  and  when  the  brood  is 
hatched,  they  begin  feeding  on  the  bark  which  had 
formed  their  cradle.  There  is.  of  course,  nothing  won- 
derful in  their  eating  the  food  selected  by  their  mother; 
but  it  appears  that,  like  the  caterpillars  of  the  clothes 
moth,  and  the  tent  insects,  they  cannot  feed  except  un- 
der cover.  They  dig,  therefore,  long  tubular  galleries 
between  the  bark  and  the  wood;  and,  in  order  not 
to  interfere  with  the  runs  of  their  brethren,  they 
branch  off  from  the  place  of  hatching  like  rays  from 
the  centre  of  a  circle:  though  these  are  not  al- 
ways in  a  right  line,  yet,  however  near  they  may  ap- 
proach to  the  contiguous  ones,  none  of  them  ever 


Bark  mined  in  rays  by  beetle  grubs. 
*  J.  R.    See  also  De  Geer,  i,  533,  &c,  apd  R  aumur,  ii,  413, 

VOL,    vi.  21* 


INSECT    TRANSFORMATIONS. 

break  into  each  other's  premises.  We  cannot  but  ad- 
mire the  remarkable  instinct  implanted  in  those  grubs 
by  their  Creator;  which  guides  them  thus  in  lines  di- 
verging farther  and  farther  as  they  increase  in  size, 
so  that  they  are  prevented  from  interfering  with  the 
comforts  of  one  another. 

The  various  instances  of  voracity  which  we  have 
thus  described  sink  into  insignificance,  when  com- 
pared with  the  terrible  devastation  produced  by  the 
larvaB  of  the  locust  (Locusta  migraloria,  LEACH), 

the  scourge  of  oriental  countries.  '  A  fire  de- 

voureth  before  them,'  says  the  Prophet  Joel,  c  and 
behind  them  a  flame  burneth:  the  land  is  as  the 
garden  of  Eden  before  them,  and  behind  them  a 
desolate  wilderness;  yea,  and  nothing  shall  escape 
them.  The  sound  of  their  wings  is  as  the  sound  of 
chariots,  of  many  horses  running  to  battle;  on  the 
tops  of  mountains  shall  they  leap,  like  the  noise  of  a 
flame  of  fire  that  devoureth  the  stubble,  as  a  strong 
people  set  in  battle-array.  Before  their  faces,  the 
people  shall  be  much  pained,  all  faces  shall  gather 
blackness.  They  shall  run  like  mighty  men;  they 
shall  climb  the  wall  like  men  of  war;  and  they  shall 
march  every  one  in  his  ways,  and  they  shall  not  break 
their  ranks;  neither  shall  one  thrust  another.'* 

The  intelligent  traveller,  Dr  Shaw,  was  an  eye- 
witness of  their  devastations  in  Barbary  in  1724, 
where  they  first  appeared  about  the  end  of  March, 
their  numbers  increasing  so  much  in  the  beginning 
of  April  as  literally  to  darken  the  sun;  but  by  the 
middle  of  May  they  began  to  disappear,  retiring  into 
the  Mettijiah  and  other  adjacent  plains  to  depo- 
sit their  eggs.  £  These  were  no  sooner  hatched 
in  June,'  he  continues,  c  than  each  of  the  broods 
collected  itself  into  a  compact  body,  of  a  furlong  or 
more  in  square;  and  marching  afterwards  directly 

*  Joel  ii,  2,  &c. 


RAVAGES    OF    LOCUSTS.  247 

forwards  toward  the  sea,  they  let  nothing  escape 
them,  —  they  kept  their  ranks  like  men  of  war;  climb- 
ing over,  as  they  advanced,  every  tree  or  wall  that 
was  in  their  way;  nay,  they  entered  into  our  very 
houses  and  bed-chambers,  like  so  many  thieves. 
The  inhabitants,  to  stop  their  progress,  formed 
trenchers  all  over  their  fields  and  gardens,  which  they 
filled  with  water.  Some  placed  large  quantities  of 
heath,  stubble,  and  other  combustible  matter,  in  rows, 
and  set  them  on  fire  on  the  approach  of  the  locusts; 
but  this  was  all  to  no  purpose,  for  the  trenches  were 
quickly  filled  up,  and  the  fires  put  out,  by  immense 
swarms  that  succeeded  each  other. 

c  A  day  or  two  after  one  of  these  hordes  was 
in  motion,  others  were  already  hatched  to  march  and 
glean  after  them.  Having  lived  near  a  month  in  this 
manner,  they  arrived  at  their  full  growth,  and  threw 
off  their  nympha-state  by  casting  their  outward  skin. 
To  prepare  themselves  for  this  change,  they  clung 
by  their  hinder  feet  to  some  bush,  twig,  or  corner  of 
a  stone;  and  immediately,  by  using  an  undulating 
motion,  their  heads  would  first  break  out,  and  then 
the  rest  of  their  bodies.  The  whole  transformation 
was  performed  in  seven  or  eight  minutes;  after  which 
they  lay  for  a  small  time  in  a  torpid,  and,  seemingly, 
in  a  languishing  condition;  but  as  soon  as  the  sun 
and  the  air  had  hardened  their  wings  by  drying  up  the 
moisture  that  remained  upon  them  after  casting  their 
sloughs,  they  resumed  their  former  voracity,  with  an 
addition  of  strength  and  agility.  Yet  they  continued 
not  long  in  this  state  before  they  were  entirely  disper- 
sed.'* 

It  is  difficult  to  form  an  adequate  conception  of 
the  swarms  of  locusts  which,  in  1797,  invaded 
the  interior  of  southern  Africa,  as  recorded  by  Mr 
Barrow,  In  the  part  of  the  country  where  he  was, 

*  Shaw'a  Travels,  p.  287. 


248  INSECT    TRANSFORMATIONS. 

the  whole  surface  of  the  ground,  for  an  area  of 
nearly  two  thousand  square  miles,  might  literally  be 
said  to  be  covered  with  them.  The  water  of  a  very 
wide  river  was  scarcely  visible,  on  account  of  the  dead 
carcases  of  locusts  that  floated  on  the  surface,  drowned 
in  the  attempt  to  come  at  the  reeds  that  grew  in  it. 
They  had  devoured  every  blade  of  grass,  and  every 
green  herb,  except  the  reeds.  But  they  are  not  pre- 
cisely without  a  choice  in  their  food.  When  they  at- 
tack a  field  of  corn  just  come  into  ear,  they  first,  ac- 
cording to  Mr  Barrow,  mount  to  the  summit  and 
pick  out  every  grain  before  they  touch  the  leaves  and 
stem,  keeping  the  while  constantly  in  motion,  with  the 
same  intent  of  destruction  always  in  view.  When  the 
larvae,  which  are  much  more  voracious  than  the  perfect 
insects,  are  on  a  inarch  during  the -day,  it  is  utterly 
impossible  to  turn  the  direction  of  the  troop,  and  this 
seems  usually  to  correspond  with  that  of  the  wind. 
Towards  the  setting  of  the  sun  the  march  is  discon- 
tinued, when  the  troop  divides  into  companies  that  sur- 
round the  small  shrubs,  or  tufts  of  grass,  or  ant- 
hills, in  such  thick  patches,  that  they  appear  like  so 
many  swarms  of  bees;  and  in  this  manner  they  rest  till 
day-light.  At  these  times  it  is  that  the  farmers  have 
any  chance  of  destroying  them;  this  they  sometimes 
effect  by  driving  among  them  a  flock  of  two  or  three 
thousand  sheep;  by  whose  restlessness  great  numbers 
of  them  are  trampled  to  death.  The  year  1797  was 
the  third  of  their  continuance  inSneuwberg;  and  their 
increase  had  been  more  than  a  million-fold  from  year 
to  year. 

This  district,  however,  had  been  entirely  free  from 
them  for  ten  years  preceding  their  visit  in  1794. 
Their  former  exit  was  singular:  all  the  full  grown 
insects  were  driven  into  the  sea  by  a  tempestuous 
north-west  wind,  and  were  afterwards  cast  up  on  the 
beach,  where  they  formed  a  bank  of  three  or  four  feet 


RAVAGES    OF    LOCUSTS.  249 

high,  and  extending  to  a  distance  of  nearly  fifty  miles. 
When  this  mass  became  putrid,  and  the  wind  was  at 
south-east,  the  stench  was  sensibly  felt  in  several  parts 
of  Sneuwberg,  although  distant  at  least  a  hundred 
and  fifty  miles.* 

Pallas  gives  a  more  detailed  account  of  the  daily 
proceedings  of  the  larvae  of  the  Italian  locust  (Lo- 
custa  Italica,  LEACH).  '  In  serene  weather,'  he 
tells  us,  (  the  locusts  are  in  full  motion  in  the  morn- 
ing, immediately  after  the  evaporation  of  the  dew; 
and  if  no  dew  has  fallen,  they  appear  as  soon  as  the 
sun  imparts  his  genial  warmth.  At  first,  some  are 
seen  running  about  like  messengers  among  the  re- 
posing swarms,  which  are  lying  partly  compressed 
upon  the  ground  at  the  side  of  small  eminences,  and 
partly  attached  to  tall  plants  and  shrubs.  Shortly 
after  the  whole  body  begins  to  move  forward  in  one 
direction,  and  with  little  deviation.  They  resemble  a 
swarm  of  ants,  all  taking  the  same  course,  at  small 
distances,  but  without  touching  each  other:  they  uni- 
formly travel  towards  a  certain  region  as  fast  as  a  fly 
can  run,  and  without  leaping,  unless  pursued;  in 
which  case,  indeed,  they  disperse,  but  soon  collect 
again  and  follow  their  former  route.  In  this  manner 
they  advance  from  morning  to  evening  without  halt- 
ing, frequently  at  the  rate  of  a  hundred  fathoms,  and 
upwards,  in  the  course  of  a  day.  Although  they  pre- 
fer marching  along  high  roads,  foot-paths,  or  open  ' 
tracts,  yet,  when  their  progress  is  opposed  by  bushes, 
hedges,  and  ditches,  they  penetrate  through  them: 
their  way  can  only  be  impeded  by  the  waters  of 
brooks  or  canals,  as  they  are  apparently  terrified  at 
every  kind  of  moisture.  Often,  however,  they  en- 
deavour to  gain  the  opposite  bank,  with  the  aid  of 
overhanging  boughs;  and,  if  the  stalks  of  plants  or 
shrubs  be  laid  across  the  water,  they  pass  in  close 

*  Barrow's  Travels  in  South  Africa,  p.  257. 


250  INSECT   TRANSFORMATIONS. 

columns  over  these  temporary  bridges,  on  which  they 
even  seem  to  rest,  and  enjoy  the  refreshing  coolness. 
Towards  sun-set,  the  whole  swarm  gradually  collect 
in  parties,  and  creep  up  the  plants,  or  encamp  on 
slight  eminences.  On  cold,  cloudy,  or  rainy  days, 
they  do  not  travel.  As  soon  as  they  acquire  wings, 
they  progressively  disperse,  but  still  fly  about  in  large 
swarms.  '* 

When  Captains  Irby  and  Mangles  were  travelling 
round  the  southern  extremity  of  the  Dead  Sea,  in  the 
end  of  May,  they  had  an  opportunity  of  observing 
these  insect  depredators.  '  In  the  morning,'  say 
they,  '  we  quitted  Shobek.  On  our  way  we  passed  a 
swarm  of  locusts  that  were  resting  themselves  in  a 
gully;  they  were  in  sufficient  numbers  to  alter  ap- 
parently the  colour  of  the  rock  on  which  they  had 
alighted,  and  to  make  a  sort  of  crackling  noise  while 
eating,  which  we  heard  before  we  reached  them. 
Volney  compares  it  to  the  foraging  of  an  army.  Our 
conductors  told  us  they  were  on  their  way  to  Gaza, 
and  that  they  pass  almost  annually.7")" 

Even  our  own  island  has  been  alarmed  by  the  ap- 
pearance of  locusts,  a  considerable  number  having 
visited  us  in  1748;  but  they  happily  perished  without 
propagating.  Other  parts  of  Europe  have  not  been 
so  fortunate.  In  1650  a  cloud  of  locusts  were  seen 
to  enter  Russia  in  three  different  places;  and  they 
afterwards  spread  themselves  over  Poland  and  Li- 
thuania in  such  astonishing  multitudes,  that  the  air  was 
darkened,  and  the  earth  covered  with  their  num- 
bers. In  some  places  they  were  seen  lying  dead, 
heaped  upon  each  other  to  the  depth  of  four  feet;  in 
others  they  covered  the  surface  of  the  ground  like  a 
black  cloth :  the  trees  bent  with  their  weight,  and  the 

*  Travels  in  Russia,  ii,  422-6. 

t  Irby  and  Mangles'  Travels  in  Egypt  and  Syria,  p.  443. 


RAVAGES    OF    LOCUSTS. 


251 


damage  the  country  sustained  exceeded  computation,* 
They  have  frequently  come  also  from  Africa  into 
Italy  and  Spain.  In  the  year  591  an  infinite  army 
of  locusts,  of  a  size  unusually  large,  ravaged  a  con- 
siderable part  of  Italy,  and  being  at  last  cast  into  the 
sea,  (as  seems  foj  the  most  part  to  be  their  fate,) 
a  pestilence,  it  is  alleged,  arose  from  their  stench, 
which  carried  off  nearly  a  million  of  men  and  beasts. 
In  the  Venetian  territory,  likewise,  in  1478,  more 
than  30,000  persons  are  said  to  have  perished  in  a 
famine  chiefly  occasioned  by  the  depredations  of 
locusts.*)" 

*  Bingley,  Anim.  Biog.,  iii,  280. 
t  Mouffet,  Theatr.  Insect.,  123. 


Locust. 


CHAPTER  X. 

Voracity  of  Caterpillars,  Grubs,  and  Maggots ;  — concluded. 

MAGGOTS. 

ADHERING  to  the  distinction  of  terming  those  larvae 
which  are  destitute  of  feet,  maggots,  we  shall  notice 
here  a  very  destructive  one,  which  is  sometimes  popu- 
larly called  the  grub,  and  sometimes  confounded  with 
the  wire  worm.*  We  allude  to  the  larvae  of  one  or  two 
common  species  of  crane  flies  (Tipulidce],  well  known 
by  the  provincial  names  of  father-long-legs,  Jeriny- 
spinners,  and  tailors.  These  insects  are  so  common 
in  some  meadows,  that,  being  very  shy  and  fearful  of 
danger,  they  rise  in  swarms  at  every  step  —  some  of 
them  flying  high,  others  only  skipping  over  the  grass, 
and  others  running  and  using  their  long  legs  as  the 
inhabitants  of  marshy  countries  use  stilts,  and  em- 
ploying their  wings  like  the  ostrich  to  aid  their  limbs. 

These  flies  deposit  their  eggs  in  the  earth;  some- 
times in  grass  fields  or  moist  meadows,  and  some- 
times in  the  tilled  ground  of  gardens  and  farms. 
For  this  purpose  the  female  is  provided  with  an  ovi- 
positor well  adapted  to  the  operation,  consisting  of  a 
sort  of  pincers  or  forceps  of  a  horny  consistence,  and 
sharp  at  the  point.  By  pressure,  as  Reaumur  says, 
the  eggs  may  be  extruded  from  this  in  the  same  way 
as  the  stone  can  be  easily  squeezed  out  of  a  ripe 
cherry  as  in  the  following  figure. 

*  See  Stickney's  Observ.  on  the  grub,  8vo.  Hull,  1800. 


MAGGOTS    OP    CRANE    FLIES.  253 


Ovipositor  and  eggs  of  the  crane  fly  (Tipula). 

The  eggs  are  exceedingly  small  and  black,  like 
grains  of  gunpowder,  and  each  female  lays  a  good 
many  hundreds.  The  position  which  she  assumes 
appears  somewhat  awkward,  for  she  raises  herself 
perpendicularly  on  her  two  hind  legs,  using  her  ovi- 
positor as  a  point  of  support,  and  resting  with  her 
fore-legs  upon  the  contiguous  herbage.  She  then 
thrusts  her  ovipositor  into  the  ground  as  far  as 
the  first  ring  of  her  body,  and  leaves  one  or  more 
eggs  in  the  hole;  and  next  moves  onwards  to  ano- 
ther place,  but  without  bringing  herself  into  a  hori- 
zontal position.  The  maggot,  when  hatched  from 
the  egg,  immediately  attacks  the  roots  of  the  grass 
and  other  herbage  which  it  finds  nearest  to  it;  and 
of  course  the  portion  of  the  plant  above  ground 
withers  for  lack  of  nourishment. 

The  maggots  of  this  family  which  seem  to  do  most 
injury  are  those  of  Tipula  oleracea  and  T.  cornicina. 
In  the  summer  of  1828,  we  observed  more  than  an 
acre  of  ground,  adjoining  the  Bishop  of  Oxford's 
garden,  at  Blackheath,  as  entirely  stripped,  both  of 
grass  and  every  thing  green,  as  if  the  turf  had  been 

VOL.  vi.  22 


254 


INSECT    TRANSFORMATIONS. 


Crane  fiy  ovipositing,  and  the  larva  beneath,  in  the  earth,  feeding 
upon  grass  roots. 

pared  off  from  the  surface,  the  only  plant  untouched 
being  the  tiny  bird  tare  (Ornithopus  perpusillus). 
On  digging  here  to  learn  the  cause,  we  found  these 
larvae  already  full-fed,  and  about  to  pass  into  pupae, 
after  having  left  nothing  upon  which  they  could  subsist. 
It  was  not  a  little  remarkable  that  they  seemed  to  be 
altogether  confined  to  this  spot;  for  we  did  not  meet 
with  a  single  foot  of  turf  destroyed  by  them  in  any 
other  part  of  the  heath,  or  in  the  adjacent  fields.  So 


RAVAGES    OF    MAGGOTS,  255 

very  complete,  however,  was  their  destruction  of  the 
roots  on  the  spot  in  question,  that  even  now,  at  the 
distance  of  two  years,  it  is  still  visibly  thinner  of 
herbage  than  the  parts  around  it.* 

Reaumur  gives  a  similar  account  of  their  ravages 
in  Poitou,  where,  in  certain  seasons,  the  grass  of  the 
low  moist  meadows  has  been  so  parched  up  in  conse- 
quence, as  not  to  afford  sufficient  provender  for  the 
cattle.  He  describes  the  soil  in  Poitou  as  a  black 
peat  mould;  and  it  was  the  same  in  which  we  found 
them  at  Blackheath,  with  this  difference,  that  the  spot 
was  elevated  and  dry.  According  to  M.  Reaumur,  also, 
their  only  food  is  this  sort  of  black  mould,  and  not  the 
roots  of  grass  and  herbage,  which  he  thinks  are  only 
loosened  by  their  burrowing.')"  This  view  of  the  matter 
appears  strongly  corroborated  by  the  fact  that  several 
species  of  the  family  feed  upon  the  mould  in  the  holes 
of  decaying  trees,  particularly  the  larva  of  a  very 
beautiful  ones  (Ctenophora  flaveolata,  MEIGJEN), 
which  is  very  rare  in  Britian.  It  is  proper  to  men- 
tion, however,  that  Mr  Stickney's  experiments,  J 
contrary  to  the  conclusions  of  Reaumur,  indicate 
that  these  larvae  devour  the  roots  of  grass;  and  Stew- 
art says  they  £  feed  on  the  roots  of  plants,  corn,  and 
grasses,  and  are  thence  destructive  to  gardens,  fields, 
and  meadows.  They  prevailed  in  the  neighbourhood 
of  Edinburgh,  and  other  places  in  Scotland,  in  the 
spring  of  1800,  when  they  laid  waste  whole  fields  of 
oats  and  other  grain.  '§ 

In  many  districts  of  England  these  insects  cut  off 
a  large  proportion  of  the  wheat  crop,  particularly,  it 
would  appear,  when  it  had  been  sown  on  clover  leys. 
'  In  the  rich  district,'  say  Kirby  and  Spence,  '  of 
Sunk  Island,  in  Holderness,  in  the  spring  of  1813, 
hundreds  of  acres  of  pasture  have  been  entirely  de-  , 

*  J.  R.  t  R  aumur,  v.  12,  &c. 

t  Obs.  on  the  Grub.  §  Elements,  ii,  267. 


256  INSECT    TRANSFORMATIONS. 

stroyed  by  them,  being  rendered  as  completely  brown 
as  if  they  had  suffered  a  three  month's  drought,  and 
destitute  of  all  vegetation  except  a  few  thistles.  A 
square  foot  of  the  dead  turf  being  dug  up,  °2lO  grubs 
were  counted  on  it;  and,  what  furnishes  a  striking 
proof  of  the  prolific  powers  of  those  insects,  last  year 
it  was  difficult  to  find  a  single  one.'* 

It  is  worthy  of  remark  that  the  mandibles  of  these 
destructive  creatures,  which  are  claw-shaped  and 
transverse,  do  not  act  against  each  other  as  is  usual 
among  insects,  but  against  two  other  pieces  which  are 
immoveable,  convex,  and  toothed,  —  as  if  the  under- 
jaw  in  quadrupeds  were  divided  into  two,  and  should 
act  vertically  on  the  two  portions  of  the  immoveable 
upper-jaw  thrown  in  between  them. 

The  maggot  of  a  minute  fly  of  the  same  family, 
known  by  the  name  of  the  wheat  fly  ( Cecido- 
myia  Tritici,  KIRBY),  is  frequently  productive  of 
great  damage  in  the  crops  of  wheat.  Its  history  was 
first  investigated  by  Marsham,  and  subsequently  by 
Kirby,  and  several  other  intelligent  naturalists.  The 
parent  fly  is  very  small,  not  unlike  a  midge  ( Culicoi- 
des  punctata,  LATH.),  of  an  orange  colour,  and  wings 
rounded  at  the  tip,  and  fringed  with  hairs. f  The 
female  is  furnished  with  a  retractile  ovipositor,  four 
times  as  long  as  the  body,  and  as  fine  as  a  hair,  for 
depositing  her  eggs,  which  she  does  in  the  glumes 
of  the  florets  of  the  grain.  The  following  account  of 
its  proceedings  is  given  by  Mr  Shireff,  an  intelli- 
gent farmer  of  East  Lothian. 

*  Wheat-flies,'  he  says,  '  were  first  observed  here 
this  season  on  the  evening  of  the  21st  of  June,  and, 
from  the  vast  number  seen,  it  is  probable  a  few  of 
them  may  have  been  in  existence  some  days  previous. 

*  Intr.  i,  318,  note, 
t  Linn.  Trans.,  iii,  234  — iv,  243-240;  v.  96. 


RAVAGES    OF    MAGGOTS.  257 

The  eggs  were  visible  on  the  23d,  the  larvae  on  the 
30th  of  that  month,  and  the  pupae  on  the  29th  of 
July,  The  flies  were  observed  depositing  eggs  on 
the  28th,  and  finally  disappeared  on  the  30th  July; 
thus  having  existed  throughout  a  period  of  thirty-nine 
days. 

4  The  flies  were  observed  to  frequent  the  wheat- 
plant,  including  the  thick-rooted  couch-grass  (  Triti- 
cuin  repens).  They  generally  reposed  on  the  lower 
parts  of  the  stems  during  the  day,  and  became  active 
about  sunset,  except  when  the  wind  was  high.  I 
have,  however,  seen  them  flying  about  on  cloudy 
mornings,  till  seven  o'clock;  and,  upon  one  occasion, 
witnessed  them  depositing  .their  eggs,  in  a  shaded 
situation,  at  two  in  the  afternoon.  Their  movements 
appear  to  be  influenced  by  the  rays  of  light,  of  which 
they  seem  impatient,  being  active  when  the  sun  is 
below  or  near  the  horizon;  they  frequent  the  most 
umbrageous  part  of  the  crop,  and  shun  that  which  is 
deficient  in  foliage. 

'  The  flies  almost  invariably  preferred  the  ears 
emerging  from  the  vagina  to  those  farther  advanced, 
for  depositing  their  eggs  on;  and  as  one  side  only 
of  the  ear  is  exposed  when  the  plant  is  in  this  stage 
of  growth,  the  other  side  generally  remained  unin- 
jured. The  fly  deserted  the  fields  as  the  crop  ad- 
vanced towards  maturity,  and  were  found  longest 
on  the  spring-sown  portion  of  the  crop.  It  seemed 
to  feed  on  the  gum  adhering  to  the  newly  emerged 
ears;  and  as  there  is  a  great  diversity  in  the  time  of 
sowing  wheat  in  this  neighbourhood,  and  conse- 
quently of  the  ears  escaping  from  the  vagina,  I 
attribute  the  unusual  length  of  time  it  has  existed 
this  season,  to  the  supply  of  food  thus  gradually  fur- 
nished. 

i  The  fly  deposits  its  eggs  with  much  intensity, 
and  may  easily  be  taken  when  so  employed.  Upon 
.VOL.  vi.  22* 


258  INSECT    TRANSFORMATIONS. 

one  occasion,  I  numbered  thirty -five  flies  on  a  single 
ear;  and,  after,  carrying  it  a  distance  of  a  quarter  of 
a  mile,  six  of  them  still  continued  to  deposite  eggs. 
At  another  time,  I  placed  a  fly,  then  laying,  between 
the  face  and  glass  of  my  watch,  where  it  deposited 
several  eggs,  although  invariably  interrupted  by  the 
revolution  of  the  moment  hand. 

c  The  eggs  of  the  fly  are  generally  found  in  clus- 
ters, varying  in  number  from  two  to  ten,  upon  the 
inner  chafF,  in  which  the  furrowed  side  of  the  grain  is 
embedded,  and  are  also  occasionally  to  be  seen  in 
the  interior  parts  of  the  flower  and  chaff.  The  eggs 
are  deposited  by  means  of  a  long  slender  tube,  and 
fixed  with  a  glutinous  substance  possessed  by  the  fly. 
A  thread  of  glutinous  matter  frequently  connects  a 
cluster  of  eggs  with  the  style,  where  the  larvae  seem 
to  subsist  on  the  pollen;  in  one  instance,  fifteen  eggs 
were  numbered  on  such  a  thread,  several  of  which 
were  suspended  on  the  portion  extending  between 
the  chaff  and  the  style.  The  fly  not  only  seems  thus 
to  provide  a  convevance  from  the  larvae  to  the  style, 
but  also  food  for  their  support.  The  anthers  are  pre- 
vented from  leaving  the  style  in  consequence  of  being 
gummed  down  by  the  glutinous  matter  of  the  fly,  and 
the  pollen  thereby  detained  for  the  use  of  the  larvae, 
which  otherwise  would,  in  part,  be  carried  out  of  the 
glumes  by  the  expansion  of  the  filaments,  —  known  to 
farmers  by  the  term  bloom.  In  the  exertion  of  gum- 
ming down  the  anthers,  many  of  the  flies  are  entan- 
gled in  the  vascules  of  the  corolla,  and  thus  become  a 
sacrifice  to  their  maternal  affection. 

'  The  larvae  are  produced  from  the  eggs  in  the 
course  of  eight  or  ten  days:  they  are  at  first  perfectly 
transparent,  and  assume  a  yellow  colour  a  few  days 
afterwards.  They  travel  not  from  one  floret  to  an- 
other, and  forty-seven  have  been  numbered  in  one. 
Occasionally  there  are  found  in  the  same  floret  larvae 


RAVAGES    OF     MAGGOTS. 


259 


and  a  grain,  which  is  generally  shrivelled,  as  if  depri- 
ved of  nourishment;  and  although  the  pollen  may  fur- 
nish the  larvae  with  food  in  the  first  instance,  they 
soon  crowd  around  the  lower  part  of  the  germen,  and 
there,  in  all  probability,  subsist  on  the  matter  destined 
to  have  formed  the  grain. '* 


Germination  of  a  grain  of  wheat.  «,  the  heat  t  of  the  grain, 
the  part  devoured  by  the  insect,  fe,  bag  o  the  s^ed.  c,  the  root. 
d,  vessels  to  convey  the  nutriment  for  the  root,  e,  feathers 
conveying  the  pollen  to  fructify  the  seed. 

Another  intelligent  observer,  Mr  Gorrie,  of  Annat 
Gardens,  Perthshire,  found  that  by  the  first  of  August 
all  the  maggots  leave  the  ears,  and  go  into  the  ground 
about  the  depth  of  half  an  inch,  where  it  is  probable 
they  pass  the  winter  in  the  pupa  state. 't 

It  is  interesting  to  learn  that  this  destructive  in- 

*  Loudon's  Mag.  of  Nat.,  Hist.,  Nov.  1829.  p:  450. 
t  Ibid,  September,  1829,  p.  324. 


260  INSECT    TRANSFORMATIONS. 


Transformations  of  the  wheat  fly.    a,  the  female  fiy  magnified  ; 
6,  larvae,  natural  size,  feeding;  c,  one  magnified. 

sect  is  providentially  prevented  from  multiplying  so 
numerously  as  it  might  otherwise  do,  by  at  least  two 
species  of  ichneumons,  which  deposit  their  eggs  in  the 
larvae.  One  of  these  (Encyrtus  inserens,  LATR.)  is 
very  small,  black,  and  shining.  The  other  (Platy- 
gaster  Tipulce,  LATR.)  is  also  black,  with  red  feet,  and  a 
blunt  tail.  These  have  been  frequently  mistaken  for 
the  wheat-fly;  but  as  it  has  only  iwo  wings,  while  they 
have  four,  the  distinction  is  obvious.  In  order  to 
observe  the  proceedings  of  the  ichneumons,  Kirby 
placed  a  number  of  the  larvae  of  the  wheat-fly  on  a 
sheet  of  white'  paper,  and  set  a  female  ichneumon  in 
the  midst  of  them.  She  soon  pounced  upon  her  vic- 
tim, and  intensely  vibrating  her  antennae,  and  bending 
herself  obliquely,  plunged  her  ovipositor  into  the  body 
of  the  larva,  depositing  in  it  a  single  egg.  She  then 
passed  to  a  second,  and  proceeded  in  the  same  man- 
ner, depositing  a  single  egg  in  each.  Nay,  when 
she  examined  one  which  she  found  had  already  been 
pricked,  she  always  rejected  it  and  passed  to  another.* 
Mr  ShirefF  repeated  these  experiments  successfully, 
except  that  he  saw  an  ichneumon  twice  prick  the 
same  maggot,  which  *  writhed  in  seeming  agony,' 
and  '  it  was  again  stung  three  times  by  the  same 
fly.'  He  adds,  '  the  earwig  also  destroys  the  larvae, 
three  of  which  I  successfully  presented  to  an  earwig, 
which  devoured  them  immediately. '|  Mr  Gorrie 
describes  these  ichneumons  as  appearing  in  myriads 

*  Linn.  Trans,  ut  supra.          t  London's  Mag.  ut  supra. 


WHEAT    FLIES  261 

on  the  outside  of  the  ear;  but  as  impatient  of  bright 
light,  sheltering  themselves  from  the  sun's  rays 
among  the  husks. 

Our  English  naturalists  were  for  many  years  of 
opinion,  that  the  insect  called  the  Hessian-fly,  so 
destructive  to  wheat  crops  in  America,  belonged  to 
the  same  family  (Muscidce)  with  the  common  house- 
fly; and  Mr  Mark  wick,  an  intelligent  naturalist,  by 
a  series  of  observations  on  a  British  fly  (Chlorops 
pumilionis,  MEIGEJN)  which  attacks  the  stems  of 
wheat,  created  no  little  alarm  among  agriculturists. 
Mark  wick 'a  fly  is  less  than  a  fourth  of  an  inch  in- 
length,  with  dark  shoulders  striped  with  two  yellow 
lines,  and  the  maggot  is  white.  He  planted  roots  of 
wheat  containing  larvas  in  a  small  flower  pot,  and 
covered  them  with  gauze.  Each  stem  produced  one 
of  the  above  flies.  The  crop  of  wheat  attacked  by 
this  maggot,  though  at  first  it  appeared  to  fail, 
turned  out  well  in  consequence  of  numerous  side 
shoots.  It  is  only  the  early  wheat  sown  in  October 
that  is  affected  by  it.* 


«,  The  Hessian  fly  (Cccidomyia  d'strurtor);  5,  Markwick  fly 
((.  htoreps  fmmilionii,}  magnified. 

It  now  appears  that  Markwick  was  altoget  her 
mistaken  in  identifying  his  insect  with  the  Hessian 
fly  (Cecidomyia  destructor,  SAY),  which  has  been 
accurately  described  by  Mr  Say  in  the  '  Journal  of 
the  Academy  of  Natural  Sciences  of  Philadelphia' 

*  Mag.  Nat.  Hist.  July  1829,  p.  292. 


INSECT    TRANSFORMATIONS. 

for  1817.  It  is  a  little  larger  than  our  wheat-fly, 
more  slender  in  the  body,  has  longer  legs,  and  is 
not  orange,  but  black  and  fulvous.  The  female 
deposits  from  one  to  eight  or  more  eggs  on  a  single 
plant  of  wheat,  between  the  sheath  of  the  inner  leaf 
and  the  stem  nearest  the  roots  ;  in  which  situation, 
with  its  head  towards  the  root  or  first  joint,  the 
young  larva  passes  the  winter,  eating  into  the  stem, 
and  causing  it  to  break.  * 

The  devastation  committed  by  the  Hessian  fly 
seems  to  have  been  first  observed  in  1776,  and  it 
was  erroneously  supposed  that  the  insect  was  con- 
veyed among  straw  by  the  Hessian  troops  from  Ger- 
many. It  was  first  noticed  in  the  wheat  fields  of 
Long  Island,  from  which  it  spread  gradually  at  the 
rate  of  fifteen  or  twenty  miles  round;  and  in  1789  it 
had  advanced  two  hundred  miles  from  its  original 
station  in  Long  Island.  Other  accounts  state  that  it 
did  riot  travel  more  than  seven  miles  annually,  and 
did  little  serious  damage  before  1788.  Their  num- 
bers seem  almost  incredible.  The  houses  in  the 
infested  districts  swarmed  with  them  to  so  great  a 
degree,  that  every  vessel  was  filled  with  them;  five 
hundred  were  actually  counted  on  a  glass  tumbler 
which  had  been  set  down  for  a  few  minutes  with  a 
little  beer  in  it.  They  were  observed  crossing  the 
Delaware  river  like  a  cloud;  and  even  mountains  do 
not  seem  to  interrupt  their  progress.!  We  can  well 
understand,  therefore,  that  so  formidable  a  ravager 
should  have  caused  a  very  great  alarm;  and  even  our 
own  government  was  in  fear  lest  the  insect  should  be 
imported.  The  privy  council,  indeed,  sat  day  after 
day  in  deep  consultation  what  measures  should  be 
adopted  to  ward  off  the  danger  of  a  calamity  more  to 
be  dreaded,  as  they  well  knew,  than  the  plague  or 
the  pestilence.  Expresses  were  sent  off  in  all  direc- 

*  Mag.  Nat.  Hist,  vol.  i,  p.  228. 
t  Kirby  and  Spence,  vol.  i,  p.  172. 


CHEESE    FLY.  263 

tions  to  the  officers  of  the  customs  at  the  different  out- 
ports  respecting  the  examination  of  cargoes,  —  de- 
spatches were  written  to  the  ambassadors  in  France, 
Austria,  Prussia,  and  America,  to  gain  information,  — 
and  so  important  altogether  was  the  business  deemed, 
that  the  minutes  of  council,  and  the  documents  col- 
lected from  all  quarters,  fill  upwards  of  two  hundred 
pages.* 

As  in  the  case  of  the  English  wheat-fly,  the  Ame- 
rican Hessian  fly  has  a  formidable  enemy  in  a 
minute  four-winged  fly  (Ceraphron  destructor,  SAY), 
which  deposits  its  eggs  in  the  larvae.  Were  it  not 
for  the  Ceraphron,  indeed,  Mr  Say  is  of  opinion  that 
the  crops  of  wheat  would  be  totally  annihilated  in 
the  districts  where  the  Hessian  fly  prevails. *f 

Those  who  have,  from  popular  associations,  been 
accustomed  to  look  with  disgust  at  the  little  white 
larvae  common  in  cheese,  well  known  under  the  name 
of  hoppers,  will  be  somewhat  surprised  to  hear  the 
illustrious  Swammerdam  say,/  I  can  take  upon  me 
to  affirm,  that  the  limbs  and  other  parts  of  this 
maggot  are  so  uncommon  and  elegant,  and  con- 
trived with  so  much  art  and  design,  that  it  is  impos- 
sible not  to  acknowledge  them  to  be  the  work  of  infi- 
nite power  and  wisdom,  from  which  nothing  is  hid, 
and  to  which  nothing  is  impossible.  J'  But  who- 
ever will  examine  it  with  care,  will  find  that  Swam- 
merdam has  not  exaggerated  the  facts. 

The  cheese-fly  (Piophila  Casei,  FALLEN)  is  very 
small  and  black,  with  whitish  wings,  margined  with 
black.  It  was  one  of  those  experimented  upon  by 
Redi  to  prove  that  insects,  in  the  fabric  of  which  so 
much  art,  order,  contrivance,  and  wisdom  appear, 

*  Young,  Annals  of  Agric.,  vol.  xi. 

f  Journ.  of  A  cad.  Philadelph.  ut  supra. 

t  Bibl.  Naturae,  vol.  ii,  p.  63. 


264  INSECT    TRANSFORMATIONS. 

could  not  be  the  production  of  chance  or  rottenness, 
but  the  work  of  the  same  Omnipotent  hand  which 
created  the  heavens  and  the  earth.  This  tiny  little 
fly  is  accordingly  furnished  with  an  admirable  instru- 
ment for  depositing  its  eggs,  in  an  ovipositor,  which 
it  can  thrust  out  and  extend  to  a  great  length,  so 
that  it  can  penetrate  to  a  considerable  depth  into  the 
cracks  of  cheese,  where  it  lays  its  eggs,  256  in 
number.  4  I  have  seen  them  myself,'  says  Swam- 
merdam,  c  thrust  out  their  tails  for  this  purpose  to  an 
amazing  length,  and  by  that  method  bury  the  eggs 
in  the  deepest  cavities.  I  found  in  a  few  days  after- 
wards a  number  of  maggots  which  had  sprung  from 
those  eggs,  perfectly  resembling  those  of  the  first 
brood  that  had  produced  the  mother  fly.  I  cannot 
but  also  take  notice  that  the  rottenness  of  cheese  is 
really  caused  by  these  maggots;  for  they  both  crum- 
ble the  substance  of  it  into  small  particles  and  also 
moisten  it  with  some  sort  of  liquid,  so  that  the 
decayed  part  rapidly  spreads.  I  once  observed  a 
cheese  which  I  had  puvposely  exposed  to  this  kind  of 
fly  grow  moist  in  a  short  time  in  those  parts  of  it 
where  eggs  had  been  deposited,  and  had  afterwards 
been  hatched  into  maggots;  though,  before,  the 
cheese  was  perfectly  sound  arid  entire.'* 

The  cheese-hopper  is  furnished  with  two  horny 
claw-shaped  mandibles,  which  it  uses  both  for  dig- 
ging into  the  cheese  and  for  moving  itself,  being 
destitute  of  feet.  Its  powers  of  leaping  have  been 
observed  by  every  one;  and  Swammerdam  says,  '  I 
have  seen  one,  whose  length  did  not  exceed  the 
fourth  of  an  inch,  leap  out  of  a  box  six  inches  deep, 
that  is,  twenty-four  times  the  length  of  its  own 
body:  others  leap  a  great  deal  higher. 'f  For  this 
purpose  it  first  erects  itself  on  its  tail,  which  is  fur- 
nished with  two  wart-like  projections,  to  enable  it  to 

*  Swammerdam,  vol.  ii,  p.  69.     t  Bibl.  Nat.,  vol.  ii,  p.  65. 


CHEESE    MAGGOTS. 


265 


maintain  its  balance.  It  then  bends  itself  into  a 
circle,  catches  the  skin  near  its  tail  with  its  hooked 
mandibles,  and  after  strongly  contracting  itself  from 
a  circular  into  an  oblong  form,  it  throws  itself  with  a 
jerk  into  a  straight  line,  and  thus  makes  the  leap. 


Cheese  hoppers  (PiophUa  casei,  Fallen),  a,  the  maggot  ex- 
tended ;  £,  in  a  leaping  position  ;  rf,  the  same  magnified  ;  e,  the 
fly  magnified  ;  y,  g-,  the  fly,  natural  size.  / 

One  very  surprising  provision  is  remarkable  in 
the  breathing-tubes  of  the  cheese  maggot,  which  are 
not  placed,  as  in  caterpillars,  along  the  sides,  but  a 
pair  near  the  head  and  another  pair  near  the  tail. 
Now,  when  burrowing  in  the  moist  cheese,  these 
would  be  apt  to  be  obstructed;  but  to  prevent  this, 
it  has  the  power  of  bringing  over  the  front  pair  a 
fold  of  the  skin,  breathing  in  the  meanwhile  through' 
the  under  pair.  Well  may  Swammerdam  denomi- 
nate these  contrivances  '  surprising  miracles  of  God's 
power  and  wisdom  in  this  abject  creature.' 

Like  the  other  destructive  insects  above  mentioned, 
the  multiplication  of  the  cheese  fly  is  checked  by  some 
insect,  whose  history,  so  far  as  we  are  aware,  is  not 
yet  known.  Swammerdam  found  many  of  the  maggots 
with  other  larvae  in  their  bodies;  but  he  did  not  trace 
their  transformations.  If  they  were  the  larvae  of  an 
ichneumon,  it  must  be  exceedingly  minute. 

It  must  have  attracted  the  attention  of  the  most 
VOL.  vi.  23 


26$  INSECT    TRANSFORMATIONS. 

incurious,  to  see,  during  the  summer,  swarms  of  flies 
crowding  about  the  droppings  of  cattle,  so  as  almost 
to  conceal  the  nuisance,  and  presenting  instead  a  dis- 
play of  their  shining  corslets  and  twinkling  wings. 
The  object  of  all  this  busy  bustle  is  to  deposit  their 
eggs  where  their  progeny  may  find  abundant  food  ; 
and  the  final  cause  is  obviously  both  to  remove  the 
nuisance  and  to  provide  abundant  food  for  birds 
and  other  animals,  which  prey  upon  flies  or  their  larva?. 
The  same  remarks  apply  with  no  less  force  to  the 
blow-flies  which  deposit  their  eggs,  and  in  some  cases 
their  young,  upon  carcases.  The  common  house-fly 
(Musca  domtstica)  belongs  to  the  first  division,  the 
natural  food  of  its  larvae  being  horse-dung;  conse- 
quently it  is  always  most  abundant  in  houses  in  the 
vicinity  of  stables,  cucumber  beds,  &c,  to.  which,  when 
its  numbers  become  annoying,  attention  should  be 
primarily  directed,  rather  than  having  recourse  to  fly- 
waters. 

Another  common  insect  (Bibio  JiortulanuSj  MEI- 
GEN)  lives  in  the  larva  state  in  cesspools,  along  with 
rat-tailed  larvae,  &,c.  The  maggot  of  the  bibio  is  very 
peculiar  in  form.  They  are  hatched  from  eggs  with 
shells  as  hard  as  Paris  plaster,  deposited  on  the  adja- 
cent walls,  and  frequently  upon  the  pupa  case  which  the 
mother  has  previously  quitted.  Like  the  larva?  of  the 
crane  flies  above  described,  this  one  moves  itself  chiefly 
by  means  of  its  mandibles,  and  therefore  it  can  make  no 
progress  on  a  piece  of  smooth  glass.  Its  skin,  it  may 
be  remarked,  is  so  exceedingly  hard  and  tough,  that 
it  is  no  easy  matter  to  kill  it*  We  have  introduced 
this  insect  here,  however,  chiefly  for  the  purpose  of 
refuting  an  erroneous  popular  accusation  against 
it,  which  is  supported  by  the  high  authorities  of 
Ray  and  Reaumur.  Our  great  English  naturalist 
calls  it  the  deadliest  enemy  of  the  flowers  in  spring, 
and  accuses  it  of  despoiling  the  gardens  and  fields  of 

*  Swamrnerdain,  x,  212. 


BIBIO    HORTULANUS. 


267 


every  blossom.'*  Reaumur  is  less  decided  in  his  opi- 
nion; for  though  he  perceived  that,  not  being  fur- 
nished with  mandibles,  they  could  not,  as  is  supposed, 
gnaw  the  buds  of  fruit-trees  ;  yet,  from  their  being 
found  crowded  upon  flowers  and  buds,  he  thinks  they 
may  suck  the  juices  of  these,  and  thus  cause  them  to 
wither. |  We  are  satisfied,  by  repeated  observation, 
that  the  fly  only  uses  its  sucker  (haustellum)  for  sip- 
ping the  honey  of  flowers,  or  the  gum  with  which 
the  opening  bud  is  usually  covered.  The  damage 
of  which  it  is  accused  is  more  probably  done  by  cater- 
pillars, snails,  or  other  night-feeding  insects,  which, 
not  being  seen  by  day,  the  fly  is  blamed  for  what  it  is 
entirely  innocent  of.J 


Transformations  of  Bibio  hortulanus,  Meigen.  a,  the  egg 
magnified  ;  6,  the  same  when  hatched ;  c,  d,  the  maggot  and 
pupa  magnified  ;  e,  /,  the  same,  natural  size  ;  g-,  the  fly. 

In  the  case  of  the  blow-flies,  LinnaBus  tells  us  that 
the  larvae  of  three  females  of  Musca  vomitoria  will 
devour  the  carcase  of  a  horse  as  quickly  as  would 
a  lion ;  and  we  are  not  indisposed  to  take  this 


*  Raii  Hist.  Insect.  Pref.  p.  xi. 
J.  R. 


t  Reaumur,  v.  56. 


268  INSECT    TRANSFORMATIONS. 

literally,  when  we  know  that  one  mother  of  an  allied 
species  (M.  carnaria}  produces  about  20,000,  and 
that  they  have  been  proved  by  Redi  to  increase  in 
weight  two-hundred-fold  within  twenty-four  hours. 
The  most  extraordinary  fact,  illustrative  of  the  voracity 
of  these  maggots  which  we  have  met  with,  is  the 
following,  given  by  Kirby  and  Spence,  from  f  Bell's 
Weekly  Messenger:'  — 

'  On    Thursday,  June    25th,  died    at    Asbornby, 
Lincolnshire,    John    Page,    a    pauper   belonging   to 
Silk-Willoughby,  under  circumstances  truly  singular. 
He  being  of  a  restless  disposition,   and   not  choosing 
to  stay   in  the  \  arish  work-house,  was  in  the  habit  of 
strolling  about  the  neighbouring  villages,  subsisting  on 
the  pittance  obtained  from  door  to   door:   the  support 
he  usually  received  from  the  benevolent  was  bread  and 
meat;  and  after  satisfying  the   cravings  of  nature,  it 
was  his  custom  to  deposit  the   surplus  provision,  par- 
ticularly the  meat,  betwixt  his  shirt  and  skin.      Hav- 
irg  a   considerable  portion  of  this  provision  in  store, 
so  deposited,  he  was  taken    rather  unwell,  and  laid 
himself  down  in  a  field,  in  the  parish   of  Scredington; 
when,  from  the   heat  of  the  season  at  that  time,  the 
meat    speedily    became    putrid,  and    was    of  course 
struck  by    the    flies:    these    not    only    proceeded    to 
devour  the  inanimate  pieces  of  flesh,  but  also  literally 
to  prey    upon  the  living    substance;    and    when  the 
wretched  man  was  accidentally  found  by  some  of  the 
inhabitants,  he  was  so  eaten  by  the  maggots  that  his 
death    seemed   inevitable.     After  clearing  away,    as 
well  as  they  were  able,  these   shocking   vermin,  those 
who  found  Page  conveyed  him  to  Asbornby,  and  a 
surgeon  was  immediately  procured,  who  declared  that 
his  body  was  in  such  a  state,  that  dressing  it  must  be 
little  short   of  instantaneous   death;  and,  in  fact,  the 
man    did    survive  the    operation    but    a    few    hours. 
When  first  found,  and  again  when  examined  by  the 


UTILITY    OF    INSECTS.  269 

surgeon,  he  presented  a  sight  loathsome  in  the  ex- 
treme; white  maggots  of  enormous  size  were  crawl- 
ing in  and  upon  his  body,  which  they  had  most 
shockingly  mangled,  and  the  removing  of  the  exter- 
nal ones  served  only  to  render  the  sight  more  horrid.' 
Kirby  adds,  c  in  passing  through  this  parish  last 
spring,  I  inquired  of  the  male-coachman  whether  he 
had  heard  this  story;  and  he  said  the  fact  was  well 
known.  '*  The  year  in  which  this  remarkable  cir- 
cumstance occurred  is  not  mentioned. 

The  importance  of  the  insects  just  mentioned,  in 
removing  with  great  rapidity  what  might  otherwise 
prove  nuisances  of  considerable  magnitude,  naturally 
leads  us  to  notice  another  sort  of  larva,  no  less  useful 
in  diminishing  the  numbers  of  the  plant-lice  (Jlphides) 
which  do  so  much  damage  to  cultivated  vegetables. 
We  do  this  also  the  more  readily,  that  these  very 
insects,  which  are  so  beneficial  to  the  husbandman 
and  the  gardener,  are  often  erroneously  accused  of 
being  themselves  the  cause  of  the  mischief.  A  corre- 
spondent of  the  Natural  History  Magazine,  for  exam- 
ple, says,  *  the  lady-bird  is  remarkably  abundant  this 
season.  The  shrimp  (larva)  of  this  insect  destroys 
both  turnips  and  peas  in  many  parts  of  England,  'f 
The  truth  is,  however,  that  all  the  species  of  lady- 
birds (Coccinellidce,  LATH.),  both  in  the  larva  and  the 
perfect  state,  feed  exclusively  on  aphides,  and  never 
touch  vegetable  substances.  The  eggs  are  usually 
placed  in  a  group  of  twenty  or  more  upon  a  leaf, 
where  aphides  abound;  and  when  the  young  are 
hatched  they  find  themselves  in  the  midst  of  their 
prey.  There  are  a  considerable  number  of  species  of 
this  family  (Mr  Stephens  enumerates  fifty);  but  the 
most  common,  perhaps,  is  the  seven-spotted  lady- 
bird (Coccinella  septempunctata) ,  whose  larva  is  of 

*  Intr.  i,  140,  and  note.  t  Mag.  of  Nat.  Hist,  i,  191. 

rot,    vi       -          23* 


270 


INSECT    TRANSFORMATIONS. 


considerable    size,    and,    of  course,  when   abundant, 
must  destroy  a  vast  number  of  aphides. 


Transformations  of  the  lady-bird  (Coccindla  2-punctata,  Linn.) 
«,  the  eggs.  6,  the  larva,  c,  the  pupa,  d,  the  beetle,  e,  th» 
same  flying,  y,  Coccinella  20-punctata,  Linn.,  flying. 

The  maggots  of  many  species  of  a  beautiful  farm'lj 
(Syrphidce,  LEACH)  of  two- winged  flies  are  also 
voracious  devourers  of  the  aphides.  These  larvae  are 
of  a  tapering  form,  and  they  can  contract  or  lengthen 
their  bodies  to  a  considerable  extent;  while  they  have 
a  retractile  instrument,  armed  with  three  prongs  like 
a  trident,  with  which  they  transfix  their  helpless  and 
hapless  victims.  '  When  disposed  to  feed,'  says 
Kirby,  *  he  fixes  himself  by  his  tail,  and  being  blind, 
gropes  about  on  every  side,  as  the  Cyclops  did  for 
Ulysses  and  his  companions,  till  he  touches  one, 
which  he  immediately  transfixes  with  his  trident 


VORACITY   OF    MAGGOTS. 


271 


elevates  into  the  air,  that  he  may  not  be  disturbed  with 
its  struggles,  and  soon  devours.  The  havoc  which 
these  grubs  make  amongst  the  aphides  is  astonishing. 
It  was  but  last  week  that  I  observed  the  top  of  every 
young  shoot  of  the  currant-trees  in  my  garden  curled 
up  by  myriads  of  these  insects.  '  On  examining  them 
this  day,  not  an  individual  remained;  but  beneath 
each  leaf  are  three  or  four  full-fed  larvae  of  aphidivor- 
ous  flies,  surrounded  with  heaps  of  the  skins  of  the 
slain,  the  trophies  of  their  successful  warfare.'* 

The  larvae  of  the  lace-winged  flies  (Hemerobidce, 
LEACH)  are  even  more  destructive  to  the  aphides  than 
either  of  the  preceding;  insomuch  that  Reaumur  was 
induced  to  call  them  the  lions  of  the  aphides.  The 
mandibles  of  the  larva  of  Hemerobius  are  somewhat 
crescent-shaped,  and,  like  those  of  the  ant-lion,  are 
hollow,  by  means  of  which  they  suck  the  juices  of 
their  victims.  These  are  rarely  so  numerous  as  the 
two  preceding  families,  but  they  make  up  for  their 
fewness  in  the  voracity  with  which  they  devour  the 
little  destroyers  of  our  vegetables. 

*  Intr.  i,  264. 


a,  Lace-winged  fly  ;  5,  the  grub  of  the  same,  magnified  ;  c, 
syrphus  ;  rf,  larva  of  the  same  devouring  the  aphides  of  the  eld- 
er ;  «,  the  head  magnified,  to  show  the  mouth. 


SECTION  HI.— PUPJE. 


CHAPTER  XI. 


Mechanism  of  suspending  Chrysalides. 

A  SAILOR  would  find  it  no  easy  process  to  cut  for 
himself  a  suit  of  clothes  out  of  a  set  sail,  holding,  the 
while,  only  by  the  portion  that  he  was  cutting 
This  is  an  operation  which  is  performed  every  day  by 
the  tent-making  caterpillars.*  Difficult,  however, 
as  this  may  be  considered  to  be,  it  appears  as  nothing 
when  compared  with  another  problem  performed  by 
'a  different  family  of  caterpillars.  '  Country  fellows, 
for  a  prize,'  says  Kirby,  'sometimes  amuse  the 
assembled  inhabitants  of  a  village  by  running  races 
in  sacks :  take  one  of  the  most  active  and  adroit  of 
these,  bind  him  hand  and  foot,  suspend  him  by  the 
bottom  of  his  sack,  head  downwards,  to  the  branch 
of  a  lofty  tree;  make  an  opening  in  one  side  of  the 
sack,  and  set  him  to  extricate  himself  from  it,  to  de- 
tach it  from  its  hold,  and  suspend  himself  by  his  feet 
in  its  place.  Though  endowed  with  the  suppleness 
of  an  Indian  juggler,  and  promised  his  sack  full  of 
gold  for  a  reward,  you  would  set  him  an  absolute 
impossibility;  yet  this  is  what  our  caterpillars,  in- 
structed by  a  beneficent  Creator,  easily  perform.'')" 
The  manner  in  which  this  is  effected  we  shall  now 
describe. 

A  caterpillar,  when  about  to  change  into  a  chry 

*  See  Insect  Architecture,  p.  223.  t  Intr.  iii,  209 


SUSPENSION    OF    PUP^.  273 

sails,  usually  steals  away  from  the  plant  on  which  it 
has  been  feeding,  to  find  some  secluded  corner  where 
it  may  undergo  its  transformation  unmolested;  as  if 
it  were  previously  aware  that  it  would  no  longer  be 
able  to  escape  from  its  enemies.  Those  which  we 
shall  first  notice  climb  up  the  highest  objects  near 
them,  such  as  walls,  gates,  palings,  and  trees,  under 
the  projections  of  which  they  think  they  may  begin 
their  operations  in  safety.  Thus  we  once  found  a  ca- 
terpillar of  the  small  tortoise-shell  butterfly  upon  the 
branch  of  a  fir-tree,  in  Epping  Forest,  from  ten  to 
twelve  feet  above  its  native  patch  of  nettles  below; 
and  we  have  seen  the  cabbage  butterfly  under  the 
lintel  of  a  window  on  the  third  story. * 

Having  thus  selected  a  safe  spot,  the  caterpillar 
begins,  in  order  to  attach  itself  securely,  to  weave  a 
mooring  of  silk,  the  structure  of  which  is  well  worthy 
of  notice.  The  threads  of  which  this  is  composed  are 
so  fine,  that  they  are  not  easily  distinguished;  and 
we  recollect  being  not  a  little  astonished  at  seeing  a 
chrysalis  of  the  admirable  butterfly  ( Vanessa  JLia- 
lanta)  hanging  within  an  inverted  glass  tumbler, 
where  we  had  confined  it,  the  silk  being  transparent, 
and  all  but  invisible.  It  is  necessary,  therefore,  in 
order  to  see  it  distinctly,  to  confine  the  caterpillars 
within  a  black  box  or  other  vessel.  The  silk  threads 
are  not  drawn  tight  along,  so  as  to  be  parallel  with 
the  surface,  but  are  formed  into  a  sort  of  projecting 
button,  the  caterpillar,  for  this  .purpose,  alternately 
raising  and  depressing  its  head  over  the  spot  so  as  to 
draw  out  the  threads,  in  the  same  way  as  a  tambour- 
ing needle  is  worked  in  making  a  dot  upon  muslin: 
the  base  is  accordingly  made  the  broadest  part,  and 
the  centre  the  most  projecting,  for  a  reason  which  will 
immediately  appear. 

When    it   has    finished   this  little   button   of  silk 

*  J.  R. 


274 


INSECT    TRANSFORMATIONS 


n,  Caterpillar  of  Fanessa  Antiopa  weaving  its  button  of  silk, 
b,  suspended  by  its  hinder  pro-legs  from  the  silk  button,  c,  bend- 
ing in  order  to  split  the  old  skin. 

which  is  thickly  interlaced  and  strong,  it  turns  round 
to  examine  it  with  its  hinder  pair  of  pro-legs;  and  if 
it  judges  it  to  be  sufficiently  firm,  it  thrusts  these 
among  the  meshes,  taking  secure  hold  with  the  nu- 
merous hooks  with  which  these  are  fringed,*  and 
swings  itself  fearlessly  into  the  air,  hanging  with  its 
head  downwards.  All  this  seems  easy  enough  of 
performance,  but  it  is  only  preliminary;  for  it  has 
still  to  throw  off  its  skin,  together  with  the  hooks  by 
which  it  is  suspended,  and  this  without  losing  its 
hold.  The  old  skin  is  rent  by  the  forcible  bending 
round  of  the  upper  part  of  the  body,  which  pushes 
through  some  of  the  angular  projections  of  the  chry- 
salis —  a  tedious  and  probably  a  painful  operation,  in 

*  See  Insect  Architecture,  p.  307,  right  hand  figure. 


SUSPENSION    OF    PUP.E. 

which  it  is  often  engaged  the  greater  part  of  a  day, 
and  sometimes  two,  according  to  its  strength.  When 
the  first  rent  is  made,  however,  the  included  chrysalis 
soon  wedges  itself  through  the  breach,  the  lower  por- 
tion swelling  out  greatly  more  than  the  upper,  so  as 
to  form  an  inverted  but  somewhat  irregular  cone. 
The  included  insect  continuing  its  laborious  exertions 
by  successively  contracting  and  dilating  the  rings  of  its 
body,  pushes  off  the  now  rent  skin  by  degrees  from  the 
head  towards  the  tail,  as  the  sack-racers  mentioned 
by  Kirby  would  disengage  themselves  from  the  sacks 
in  which  they  were  inclosed,  or  as  one  would  roll 
down  a  stocking  from  the  leg.  There  are  two  cir- 
cumstances worthy  of  notice  in  this  process:  the 
position  of  the  insect  in  hanging  with  its  head  down- 
wards, throws  a  greater  portion  of  the  fluids  of  the 
body  towards  the  head,  by  means  of  their  weight, 
which  swell  out  the  part  that  splits;  and  also  pushes 
back  the  old  skin,  while  the  sloughing  skin  is  pre- 
vented from  resiliating  by  a  series  of  pegs,  which  act 
like  the  toothed  rack  of  a  sluice-gate.  The  old  skin, 
being  by  these  means  pushed  towards  the  tail,  is  of 
course  compressed  into  several  folds,  which  in  some 
degree  prevent  the  extension  of  the  rent,  and  serve 
to  keep  the  chrysalis  from  falling;  for  being  now 
detached  from  the  skin,  it  has  no  hold  upon  the 
meshes  of  the  silk  button,  and  is,  in  fact,  at  some 
distance  from  it. 

This,  then,  is  the  part  of  the  process  where  the 
"nicety  of  the  mechanism  is  most  worthy  of  admira- 
tion; for  the  hooks  by  which  the  insect  is  in  the  first 
instance  suspended  from  the  meshes  of  the  silk  are 
sloughed  off,  together  with  the  skin,  the  grasp  of 
whose  folds  becomes  then  the  only  support  of  the 
chrysalis.  But  this  chrysalis,  now  deprived  of  feet, 
and  some  distance  from  the  suspensory  cordage  of  silk, 
has  still  to  reach  this,  fix  itself  there,  and  cast  off  the 


276 


INSECT    TRANSFORMATIONS. 


sloughed  skin  altogether.  This  operation  causes,  says 
Bonnet,  a  spectator  to  tremble  for  the  consequences, 
for  every  movement  seems  to  render  its  fall  almost 
certain.  It  is,  however,  provided  with  means  which 
answer  the  same  purpose  as  hands,  to  enable  it  to 
climb;  it  can  elongate  and  contract  at  pleasure  the 
rings  of  its  body.  It  accordingly,  with  two  con- 
tiguous rings,  lays  hold,  as  with  a  pair  of  pincers,  of 
the  portion  of  the  sloughed  skin  nearest  the  head;  and 
elongating  the  rings  beyond  this,  seizes  upon  a  more 
distant  portion,  while  it  lets  go  the  first.  Repeating 
this  process  several  times,  it  at  length  arrives  at  the 
silk  button. 


a,  suspended  caterpillar  of  Vanessa  Antiopa  splitting  its  skin 
for  the  evolution  of  the  chrysalis,  fe,  the  head  of  the  chrysalis 
emerging,  c,  the  same  process  farther  advanced,  d,  the  per- 
fect pupa. 

The  tail  of  a  chrysalis,  to  an  ordinary  observer, 
would  appear  smooth,  and  quite  unfitted  for   being 


SUSPENSION    OF    PUP.E.  277 

fixed  to  the  silk  in  such  a  manner  as  to  sustain  its 
weight  ;  but  careful  examination  discovers  that  it  has 
been  furnished  with  an  efficient  apparatus  for  this 
purpose,  in  a  number  of  very  minute  hooks,  similar 
to  those  of  the  pro-legs  which  have  been  sloughed  off. 
Feeling  about  then  with  its  tail  for  the  silk,  it  insinu- 
ates these  hooks  among  the  meshes,  and  being  no 
longer  in  danger  of  falling,  it  can  swing  secure, 
as  it  had  previously  done  in  the  caterpillar  state. 

Reaumur  has,  however,  seen  some  chrysalides 
fall  before  they  completed  the  process,  in  conse- 
quence, as  he  thinks,  of  having  spun  too  slight  a 
mesh- work  of  silk.  In  order  to  ascertain  the  cor- 
rectness of  this  inference,  we  tried  a  series  of  experi- 
ments upon  a  considerable  number  of  a  brood  of  the 
peacock  butterfly  (Vanessa  Jo),  the  same  upon  which 
Reaumur  made  his  observations.  We  allowed  some 
to  spin  only  half  the  usual  portion,  and  removed  them 
to  another  station.  Here  they  eagerly  recommenced 
the  task,  and,  if  left  unmolested,  never  fell  from  the 
spot;  but  if  previously  removed  a  second  time,  they 
seldom  succeeded  in  completing  the  process  in  the 
usual  way.  They  did  not,  indeed,  in  such  cases, 
attempt  spinning  an  imperfect  silken  suspensory  ;  but 
abandoning  in  despair  what  they  felt  themselves  in- 
capable of  performing,  they  crept  down  to  the  bottom 
of  the  nurse  box,  and  cast  their  skins  without  having 
anything  to  which  they  could  attach  themselves.* 

When  the  hooks  of  a  chrysalis  have  been  properly 
fixed  among  the  meshes,  it  remains  suspended  con- 
tiguous to  the  skin  which  it  has  just  cast  ;  but  not 
liking  the  neighbourhood  of  its  now  useless  spoil,  it 
sets  itself  to  get  rid  of  it.  For  this  purpose  it  con- 
torts itself  in  various  ways,  sometimes  assuming  a 
figure  similar  to  an  S,  so  that  it  may  push  against 

*  J.  R. 
VOL.  vi.  24 


273 


INSECT    TRANSFORMATIONS. 


the  spines  of  the  old  skin  ;  and  then  giving  itself  a 
sudden  jerk,  it  spins  itself  rapidly  round  a  dozen  or 
twenty  times.  R  aumur  says  that  this  gyration 
usually  throws  off  the  slough,  in  consequence  of  its 
being  farther  from  the  centre  of  motion,  and  there- 
fore exposed  to  a  greater  centrifugal  force  ;  but  un- 
luckily for  this  refined  philosophy,  it  is  not  the  silk 
button,  but  the  chrysalis  which  spins  round,  and  con- 
sequently the  old  skin  does  not  twirl  at  all,  and  only 
moves  like  a  pendulum;  — the  best  method,  evidently, 
of  disengaging  the  hooks  it  hangs  by.  Besides,  the 
threads  of  the  silk  are  not  broken  by  the  gyration,  as 
Reaumur,  followed  by  Kirby  and  Spence,  asserts  ; 
otherwise  the  weight  of  the  chrysalis  would  to  a  cer- 
tainty break  its  threads,  more  easily  than  the  sup- 
posed centrifugal  force  would  break  those  which 
suspend  the  slough.  Repeated  observation  has  satis- 
fied us,  therefore,  that  the  twirling  of  the  chrysalis  is 
both  for  the  purpose  of  disengaging  the  old  skin  arid 
strengthening  its  own  hold.*  Bonnet  may  be  right 
or  wrong  in  thinking  the  stimulus  of  the  spines  of  the 
old  skin  is  the  cause  of  the  twirling  :  we  have  ob- 
served that  the  insects  which  change  into  chrysalideSj 


o,  o,  front  and  side  view  of  chrysalides  of  fam-ssa  vrti, 
pended  by  their  anal  hooks.  ,-,  anal  hooks  magnified. 
skin  fallen  off. 

*  J.  K. 


sus- 
.%  old 


SUSPENSION    OF    PUP.&.  279 

after  being  removed  from  their  suspensories,  also  foil 
about  and  manifest  great  uneasiness.* 

But  this  is  only  one  mode  by  which  chrysalides 
are  suspended;  for  natuie,  rich  in  variety,  has  taught 
others  to  employ  a  different  mechanism,  and  consid- 
erably more  complicated,  not  only  fixing  themselves 
by  the  tail,  but  throwing  around  their  body  a  girdle 
of  silk,  which  binds  it  firmly  to  the  spot  selected,  and 
frequently  in  a  horizontal  position.  Amongst  those, 
the  caterpillars  of  the  pretty  butterflies  called  by  col- 
lectors hairstreaks  (Theclce,  FABR.),  are  remarkable, 
both  for  their  resemblance  in  shape  to  the  common 
woodlouse  (Oniscus),  and  for  their  singular  proceed- 
ings. In  order  to  construct  a  silken  cincture  around  the 
middle  of  its  body,  after  it  has  secured  itself  at  the  tail, 
the  Thecla  draws  back  its  head,  and  pushing  out  its 
spinneret  on  one  side,  forms  an  arched  thread  by  pass- 
ing it  over  to  the  other  side.  It  then  insinuates  its 
head  under  this  thread,  and  pressing  the  fore  part  of  its 
body  down  as  closely  as  possible,  it  contrives  to  place 
the  girth  over  its  middle.  This  circumstance  is  the  more 
remarkable  when  it  is  considered  that  the  silk  is  so 
fine  as  scarcely  to  be  distinguishable  to  the  eye,  and 
that  the. back  of  the  caterpillar  over  which  it  has  to  pass 
is  thickly  bestudded  with  spines.  The  caterpillars,  in- 
deed, of-  this  whole  family  (Lyccenceidce,  LEACH), 
which  includes  our  splendid  blue  and  copper  butter- 
flies, seern  to  follow  the  same  process,  repeating  it 
from  thirty  to  fifty  times,  in  order  to  strengthen  the 
band.  As  the  caterpillars  of  the  family  just  men- 
tioned are  but  seldom  found,  those  who  are  desirous 
of  observing  the  formation  of  the  cincture  of  a  chry- 
salis may  readily  gratify  their  curiosity  by  watching 
a  brood  of  any  of  the  native  white  butterflies,  as 
those  of  the  cabbage  or  of  the  hawthorn  (Pieris 
Cratcegi,  STEPHENS).  A  caterpillar  of  this  kind, 

*  Bonnet,  OEuvres,  vol.  ii,  p.  109, 


280  INSECT    TRANSFORMATIONS. 

however,  though  it  forms  a  silken  suspensory  girth 
similar  to  the  Lyccenceidce,  constructs  it  in  a  different 
manner.  Instead  of  retracting  its  head,  it  takes 
advantage  of  its  great  pliability,  and  bending  itself 
nearly  double,  fixes  a  thread,  carrying  it  over  to  the 
other  side  simply  by  turning  its  head.  It  repeats 
this  process  a  great  number  of  times,  till  it  has 
formed  a  packet  of  threads  sufficient  for  its  cincture. 
It  then  stretches  its  head  out  into  a  right  line  with 
the  body,  and  remains  in  this  position  till  it  casts  its 
skin.  The  usual  position  of  the  chrysalides  belong- 
ing to  the  family  (Papilionidce,  LEACH)  in  question, 
is  horizontal;  but  they  frequently  also  hang  vertically, 
and  at  different  angles.  We  possess  one  of  the  large 
garden  white  butterfly  (Pontia  Brassicce),  which 
was  bound  horizontally  on  the  upper  surface  of  a 
leaf  of  the  abele  tree  (Populus  alba),  being  laid,  and 
not  hung,  as  is  almost  the  invariable  practice  of  the 
species.  The  leaf,  moreover,  is  drawn  together  in 


cr,  Caterpillar  of  the  black-veined  white  butterfly  spinning  Its 
suspensory  band.    6,  chrysalis  horizontally  bound  to   a  branch.  f 
c,  the  butterfly  (Pieria  Cratcegi,)  smaller  than  in  nature.    * 


SUSPENSION    OF   PUP^E.  281 

the  manner  of  the  leaf-rollers,  another  most  unusual 
and  remarkable  circumstance.^ 

Another  caterpillar  of  the  same  family,  that  of 
the  swallow-tailed  butterfly  (Papilio  Machaon, 
LINN.),  one  of  our  finest  but  local  native  insects, 
rhaving  a  body  less  pliable  than  the  preceding,  has 
cecourse  to  a  still  different  method  of  forming  a 
pincture.  The  proceedings  of  this  beautiful  cater- 
tillar,  distinguished  by  two  retractile  horns,  like 
hose  of  a  snail,  may  be  illustrated  by  the  mode  in 
which  a  skein  of  silk  is  wound  from  the  hand.  The 
insect  first  attaches  the  end  of  his  thread  to  the  spot 
selected  for  hanging  up  the  chrysalis,  such  as  the 
bend  of  a  branch  of  fennel  or  wild  carrot,  on  which  he 
has  been  feeding;  and  extends  it  outwards  by  the 
hooks  on  his  claws,  by  which  means  he  keeps  it 
stretched  till  he  fixes  it  on  the  other  side,  forming  a 


a,  Caterpillar  of  the  swallow-tailed  butterfly,  v.reaving  its  sus- 
pensory cincture.  6,  the  caterpillar  suspended  for  its  change, 
c,  the  chrysalis  suspended  in  a  similar  manner. 

*  J.  R. 
VOL.  vi.  24* 


282  INSECT    TRANSFORMATIONS. 

loop  about  twice  the  diameter  of  his  body.  He  re- 
peats this  process  successively  till  he  has  spun  forty, 
sixty,  or  as  many  threads  as  he  deems  strong  enough 
for  his  cincture;  and  then  throwing  it  over  his  head 
towards  the  middle  of  his  body,  he  proceeds  to  dis- 
encumber himself  of  his  old  skin. 

As  the  numerous  threads  composing  the  cincture 
are  not  glued  together,  but  remain  separate,  it  some- 
time happens  that  they  slip,  in  whole  or  in  part,  from 
the  claws  of  the  caterpillar;  and  R<  aumur  had  one 
which  was  foiled  in  all  its  efforts  to  repair  such  an 
accident.  It  did  not,  indeed;  make  any  attempt  to 
spin  a  fresh  cincture,  probably  from  its  materials 
being  exhausted  or  from  want  of  strength;  so  that 
when  it  could  not  recover  the  fallen  and  entangled 
threads,  it  collected  a  few  of  them,  suspended  in 
which  it  cast  its  skin,  but  they,  being  too  weak  to  sus- 
tain it,  gave  way,  and  it  fell  and  perished.* 

We  will  not  revert  in  this  place  to  the  varied  con- 
trivances of  those  insects  which  construct  coverings 
either  of  silk  or  other  materials  for  inclosing  their 
pupce,  such  as  the  silk-worm,  the  puss-moth  cater- 
pillar, the  tent-makers,  &c;  but  there  is  one  family 
whose  proceedings  are  so  singular  that  they  well 
merit  investigation.  We  refer  to  the  numerous  spe- 
cies of  what  are  indefinitely  termed  common  flies, 
(Muscidce^,  and  some  families  allied  to  them.  Un- 
like most  other  larvae,  these  never  cast  their  skins, 
not  even  when  they  change  into  pupae.  The  mag- 
got of  the  common  blow-fly  (Musca  vomitoma),  for 
example,  when  about  to  undergo  its  transformation, 
quits  the  carcase  where  it  has  been  feeding,  and  bur- 
rows for  an  inch  or  two  into  the  first  soft  earth  it  can 
meet  with.  Here  it  draws  in  its  body  into  a  shorter 
compass,  and  the  soft  skin  being  thus  condensed, 

*  Mem.  sur  les  Insectes,  vols.  i,  ix. 


CONTRACTION    OF     PUPJ3.  283 

it  acquires  in  thickness  what  it  loses  in  extension:  its 
moisture,  also,  disappearing  by  evaporation,  or  more 
probably  by  internal  absorption,  it  becomes  hard  and 
tough,  like  thin  parchment,  and  of  a  dull  reddish- 
brown  colour.  The  form  is  now  that  of  an  oblong 
ball;  and  it  was  from  that  circumstance  termed  an  egg 
by  Redi  and  other  early  naturalists,  —  a  term  at  which 
Svvammerdam  takes  great  offence  in  this  instance. 
The  various  changes  undergone  by  the  included  insect 
were  traced  from  hour  to  hour  by  Reaumur  with  his 
usual  patience  and  accuracy:  but  few  of  the  minute 
circumstances  detailed  by  him  would  probably  interest 
our  readers  ;  except  that  in  casting  its  mandibles, 
which  are  henceforth  useless,  they  are  not  thrown  off 
on  the  outside  of  the  case,  but  remain  on  the  inside. 

Were  such  an  extraordinary  transformation  as  this 
to  happen  to  one  of  the  larger  animals,  it  would  be 
held  forth  as  altogether  miraculous.  Were  a  lion  or 
an  elephant,  for  example,  to  coil  itself  up  into  a  ball, 
compressing  its  skin  into  twice  the  thickness  and  half 
the  extent,  while  it  remained  uniform  in  shape  and 
without  joinings  or  openings;  and,  at  the  same  time, 
were  it  entirely  to  separate  its  whole  body  from  this 
skin,  and  lie  within  it,  as  a  kernel  does  in  a  nut,  or  a 
chick  in  an  egg,  throwing  off  its  now  useless  tusks 
into  a  corner,  — and  then,  after  a  space,  should  it 
acquire  wings,  break  through  the  envelope,  and  take 
its  flight  through  the  air,  —  there  would  be  no  bounds 
to  our  admiration.  Yet  the  very  same  circumstances 
in  miniature  take  place  every  day  during  summer, 
almost  under  the  eye  of  every  individual,  in  the  case 
of  the  blow  fly,  without  attracting  the  attention  of  one 
person  in  a  million. 

The  maggots  of  the  genus  of  two-winged  flies 
(Syrphidce)  mentioned  above  as  feeding  voraciously 
on  aphides,  do  not,  like  those  of  the  blow-fly,  burrow 
in  the  earth,  but  attach  themselves  to  a  leaf  or  a 


284 


INSECT    TRANSFORMATIONS. 


branch.  Being  furnished  with  a  species  of  adhesive 
gluten,  a  maggot  of  this  sort  applies  a  portion  of  this 
with  its  mouth  to  the  spot  which  it  has  selected  for 
its  transformation,  and,  pressing  its  body  upon  it, 
becomes  immoveably  glued  down  there.  When  thus 
securely  fixed,  it  contracts  and  shortens  its  body 
similarly  to  the  maggpt  of  the  blow-fly;  but,  instead  of 
becoming  like  that,  uniformly  oblong,  the  head  swells 
out  and  the  tail  becomes  slender,  {ill  it  terminates  in 
a  point,  just  reversing  the  previousjbrm  of  the  mag- 
got, which  is  rounded  at  the  tail  and  pointed  at  the 
head.  When  the  change  is  completed,  indeed,  it 
is  a  good  deal  in  the  form  of  one  of  Prince  Rupert's 
glass  drops.  When  we  first  met  with  these  pupae,  in- 
deed, we  concluded  they  were  galls,  arid  were  not  a 
little  surprised  to  see  large  wasp-looking  fiies  issue 
fromtfiem;  but  as  they  may  be  found  in  considerable 
abundance,  it  becomes  easy  to  gratify  curiosity  and 
to  confirm  the  facts  just  stated.  It  may  not  be  out  of 
place  to  remark,  that  several  species  of  ichneumon 


o,  Pupa  of  blow  fly.    6,  the  s:>.me  magnified,    r,  head  of  pupa- 
rium  opened  10  show  the  cast  mandibles,    d,  pupa  of 


PUP^E    OF    LADY-BIRD.  285 

flies  make  reprisals  upon  them  for  their  destruction  of 
the  helpless  aphides.  Swarnmerdam  observed  eight 
of  these  parasites  issue  from  one  pupa  of  a  Syrphus.* 

The  lady-birds  (CoccindlidcR)  glue  their  pupae  to 
leaves  in  much  the  same  manner  with  the  flies  just 
mentioned:  but  their  skin,  instead  of  becoming  smooth, 
wrinkles  up  by  the  shortening  of  the  body  of  the 
grub;  because  it  is  not  so  soft  and  pliable,  and 
cannot,  therefore,  be  compressed.  The  interior,  how- 
ever, is  smooth. ^ 

Those  insects  which  live  during  their  first  stages 
in  the  water,  exhibit  a  very  different  economy  when 
they  change  from  larvae  into  nymphs,  as  may  be 
exemplified  in  the  May-flies  (Ephemeridce)  and  the 
dragon- flies  (Libellulina).  But  as  these  will  require 
to  be  described  in  a  future  page,  we  shall  content  our- 
selves at  present  with  an  account  of  an  interesting 
but  minute  species  of  tipulidan  gnat  ( Corethra  plu- 
micorwis,  MEIGEN),  of  a  straw  colour,  whose  history 
was  first  given  by  Reaumur  and  De  Geer.  The 
latter  was  induced,  from  the  beautiful  transparency 
of  the  larva,  to  name  it  Tipula  cristallina, —  a  qua- 
lity which  renders  it,  its  size  being  also  very  minute, 
rather  difficult  to  discover:  it  is  however,  a  good 
subject  for  microscopical  observations.  Taking  ad- 
vantage of  the  recent  improvements  in  microscopes, 
Dr  Goring  has  accordingly  given  coloured  figures 
both  of  the  larva  and  pupa,  as  observed  by  him,  in 
which  he  has  added  a  few  minute  detailsj  that  are 
not  in  the  otherwise  very  accurate  figures  of  R/au- 
mur. 

The  larva  is  rather  less  than  a  quarter  of  an  inch 
long,  and  somewhat  resembles  in  form  those  of  the 
same  family,  particularly  in  the  parts  about  the  head, 

*  Part  ii,  p.  99.  t  J.  R. 

$  Goring  and  Prilchard's  Nat.  Hist.,  No.  1;  and  Reaumur, 
vol.  v.,  mera  1. 


286  INSECT    TRANSFORMATIONS. 

the  mandibles  being  horny,  jointed,  and  capable  of 
uniting  into  one  pointed  borer.  The  tail  is  furnished 
with  plumed  bristles,  wuich  appear  to  serve  the  pur- 
pose of  fins.  The  nearer  this  crystaline  larva  is  to 
its  transformation,  the  more  distinctly  may  be  seen 
four  kidney-shaped  transparent  bodies,  of  a  brown 
colour,  a  pair  on  the  fourth  ring  from  the  tail,  and 
another  pair  at  the  shoulders.  The  former,  perhaps, 
serve  to  inclose  the  tail  fins  of  the  pupa;  the  latter 
the  horns  of  the  pupa,  which  again  encase  the  an- 
tennas of  the  gnat;  but  in  another  species  (Corethra 
culiciformis)  _De  Geer  supposed  these  to  be  respi- 
ratory organs.  We  are  not  aware  that  this  larva  has 
been  actually  seen  to  cast  its  skin,  but  there  can  be 
no  doubt  of  the  fact,  for  Reaumur  found  exuviae  at 
the  bottom  of  the  glasses  where  he  kept  them;*  and 
we  are  not,  consequently,  authorized  to  assert  that  its 
transformation  is  4  not  effected,  as  in  other  insects, 
by  casting  the  outer  skin,  but  by  an  actual  conver- 
sion of  one  form  of  matter  into  another. '|  We 
watched  above  a  hundred  of  them  without  being  so 
fortunate  as  to  see  their  transformation  into  pupae, 
though  we  more  than  once  observed  the  emergence 
of  the  fly. 

Our  chief  reason,  however,  for  introducing  it  here, 
is  to  show  the  mode  in  which  the  pupa  is  suspended, 
or  rather  buoyed  up,  in  the  water,  by  means  of  its 
foliated  tail  and  the  shape  of  its  body,  which  is 
bulged  out  above,  and  narrowed  as  it  approaches  the 
lower  extremity.  It  is,  besides,  very  lively  in  the 
pupa  state,  and  jerks  about  with  great  .agility,  but 
usually  keeps  close  to  the  surface  of  the  water,  so  as 
to  project  its  horns  or  antennae  cases  above  it.  In, 
the  figures  we  have  endeavoured  to  combine  the 
details  of  Reaumur  and  Dr  Goring. 

*  Reaumur,  vol.  v.,  p.  41-2. 

f  Goring  and  Pritchard,  Nat,  Hist.,  No.  1,  p.  23, 


PUP.E    OF    GNATS. 


287 


#,  a  larva  of  Ccrcihra  plumicornis  magnified.  6,  the  man- 
dibles and  palpi,  c,  the  respiratory  fins.  «,  the  pupa  magnified, 
e,  pupa,  natural  size.  /,  larva,  natural  size,  t,  the  female  fly. 
h,  the  male  fly . 

We  possess  a  small  aquatic  pupa  which  is  furnished 
at  the  tail  with  four  horny  hooks  resembling  the 
prickles  on  the  stem  of  a  rose-tree,  and  evidently 
intended  as  suspensory  appendages.  It  was  found 
hanging  to  a  deal  board,  which  had  been  immersed 
in  running  water,  and  seems  from  its  form  to  be  the 
pupa  of  a  moth  (Hydrocampa?)* 

*  J.  R. 


CHAPTER  XII. 

Form  and  Structure   of  Pupae. 

THE  figures  delineated  in  the  preceding  chapter 
show  how  different  in  form  many  pupae  are,  both  from 
their  larvae  and  from  the  insects  to  be  afterwards 
evolved  from  them,  —  as  different,  indeed,  as  the  form 
of  a  bud  from  the  seedling  tree,  or  from  the  leaf, 
branch,  or  blossom,  which  is  destined  to  shoot  from  it. 
Pupae,  as  we  formerly  remarked,  have  as  striking  an 
analogy  to  the  buds  of  plants,  as  eggs  have  to  seeds; 
—  and  this  is  the  more  necessary  to  be  insisted  on, 
that  their  nature  has  been  grossly  misrepresented 
even  by  authors  of  eminence,  and,  in  other  matters,  of 
unquestionable  accuracy.  The  term  Metamorphosis, 
so  long  applied  to  the  various  stages  of  insect  life, 
has  been  one  of  the  chief  means  of  propagating  the 
erroneous  views  in  question,  inasmuch  as  it  implies 
a  supernatural  change  like  those  described  in  the 
poetical  fables  of  Ovid.  The  term  Transformation, 
though  not  perhaps  free  from  a  similar  implication, 
is  much  less  strong  and  less  likely  to  mislead. 

That  our  objection  does  not  originate  in  hypercri- 
tical nicety,  but  is  of  no  little  importance  with  regard 
to  the  accurate  knowledge  of  the  history  of  insects, 
could  be  proved  by  reference  to  many  well-known 
works  of  natural  history;  but  we  shall  limit  our 
illustrations  to  one  or  two  of  those  strange  fancies 
which  have  obscured  and  perplexed  this  branch  of 
our  subject. 

We  shall  begin  with  the  illustrious  Harvey,  —  the 
discoverer  of  the  circulation  of  the  blood,  —  who,  in 


OPINIONS    RESPECTING    INSECTS,  C289 

his  exercitations  on  the  generation  of  animals,  says  — 
*  There  are  two  ways  in  which  we  observe  one  thing 
to  be  made  out  of  another  (as  out  of  matter),  both 
in  art  and  nature,  especially  in  the  generation  of 
animals:  one  is,  when  a  thing  is  made  out  of  ano- 
ther already  in  being,  as  a  bed  out  of  wood,  and 
a  statue  out  of  a  stone;  when,  for  example,  all 
the  materials  of  the  workmanship  exist  before  the 
workman  begins  the  work  or  attempts  to  give  it  any 
form.  The  other  way  is,  when  the  stuff  receives  both 
being  and  form  at  the  same  time.  As,  therefore,  the 
works  of  art  are  performed  two  ways  ;  the  one  by  the 
workman's  dividing,  cutting,  and  paring  away  the 
matter  prepared  for  those  operations,  so  as  to  leave 
behind,  like  a  statuary,  the  figure  of  the  thing  he 
intends  to  make:  the  other,  by  the  workman's  adding 
and  moulding,  as  well  as  paring  away,  the  materials, 
and  at  the  same  time  tempering  the  matter  itself,  so 
as  to  produce,  like  a  potter,  the  figure;  which,  for 
this  reason,  may  be  said  to  be  made,  rather  than 
formed;  —  in  the  same  manner  it  happens  in  the 
generation  of  animals ;  some  of  which  are  formed  and 
transfigured  out  of  matter  already  digested  and  in- 
creased for  this  purpose,  all  the  parts  springing  out 
together  distinctly  by  a  kind  of  metamorphosis,  and 
thus  forming  a  perfect  animal,  while  other  animals  are 
made  piece  by  piece.' 

He  proceeds  to  tell  us,  that  the  generation  of  insects 
is  performed  after  the  first  manner;  the  egg,  by 
metamorphosis,  producing  the  worm;  or  matter  in  a 
state  of  putrefaction,  when  it  becomes  too  dry  or  too 
moist,  producing  the  primary  rudiments;  and  these 
again,  by  metamorphosis,  a  caterpillar,  which,  when 
grown  to  its  full  size,  is  metamorphosed  into  an  aurelia 
(pupa),  a  butterfly,  or  a  common  fly.  '  Bees,'  he 
subjoins,  c  wasps,  hornets,  or  butterflies,  and  whatever 

VOL.  vi.  25 


'290  INSECT    TRANSFORMATIONS, 

other  animals  are  generated  by  metamorphosis  from  a 
creeping  insect,  are  said  to  be  the  offspring  of  chance, 
and  therefore  never  to  keep  up  their  species.  But 
the  lion  or  cock  are  never  produced  spontaneously  or 
by  chance.  In  the  generation  by  metamorphosis, 
animals  are  fashioned  as  it  were  by  the  impression  of 
a  seal,  or  framed  in  a  curious  mould,  all  the  matter  of 
which  they  consist  being  transformed.'* 

Goedart,  a  later  naturalist  of  eminence,  both  falls 
into  the  foolish  fancy  of  supposing  that  the  form  of 
the  human  face  can  be  traced  in  the  chrysalis,  of 
which  he  has  actually  given  a  figure  in  his  plates, 
as  Reaumur  has  done  after  him;  and  also  tells  us, 
c  that  wherever  the  legs  are  situated  in  the  cater- 
pillar, there  is  placed  the  back  of  the  insect  which  is 
to  arise  by  transmutation;  and,  on  the  contrary, 
where  the  back  of  the  caterpillar  was,  there  are  the 
legs  in  the  insect  to  be  produced  from  it.  This 
metamorphosis,'  he  adds,  '  is  performed  in  a  short 
space  of  time,  so  that  it  may  be  distinctly  seen;  be- 
cause, immediately  after  shedding  its  skin,  this  change 
appears  to  the  eye.'t 

Had  this  most  absurd  and  untrue  doctrine  passed 
into  oblivion,  or  become  obsolete,  we  should  have 
passed  it  by  in  silence;  but  as,  like  many  of  the 
theories  of  former  ages,  it  often  meets  us  even  in* 
modern  books,J  where  we  might  least  expect  to  find 
it,  we  deemed  it  proper  to  give  it  in  the  language  of 
two  of  its  most  eminent  advocates,  which  Swammer- 
dam  justly  says  contains  almost  as  many  errors  as 
words.  The  best  method  of  opposing  and  over- 
turning error  being  the  simple  explanation  of  the 
truth,  we  shall  proceed  to  describe  the  form  and 

Harvey,   de  General.  Anim.,  Esercit.  xlv. 
t  De  tnsectis,  Exp.  77. 
+  See  our  quotation  from  Goring  and  Pritchard,  p.  286 


STRUCTURE    OF    PUP^.  291 

structure  of  pupae,  rather  than  stop  to  refute  cir- 
cumstantially the  preceding  theory  of  Harvey  and 
Goedart. 

In  the  pupa  state,  then,  we  may  remark,  that  the 
legs,  wings,  and  other  external  appendages  of  the 
insect,  are,  in  the  greater  number  of  instances,  closely 
folded  up  and  enveloped  by  an  external  covering, 
usually  of  a  membranous  structure,  and  differing 
considerably  both  from  the  skin  of  the  larva  and  from 
that  of  the  perfect  insect.  It  is  as  different,  indeed, 
as  the  winter  envelope  of  the  bud  of  a  tree  is  from 
the  bark  or  from  the  cuticle  of  a  leaf.  The  angular 
forms  exhibited  in  some  chrysalides,  are  for  the  pur- 
pose of  encasing  particular  limbs,  &,c,  of  the  insect 
which  Providence  has  not  seen  meet  to  fold  down 
smoothly  to  the  body.  The  spines,  hooks,  and  hairs, 
again,  which  are  also  of  occasional  occurrence,  and 
which  Goedart  strangely  enough  mistook  for  feet,* 
are  manifestly  for  aiding  the  animal  in  casting  its  old 
skin,  as  has  been  explained  in  a  preceding  page; 
while  the  grooves,  ridges,  and  other  markings,  are 
the  indications  of  the  various  members  of  the  insects 
folded  up,  or  otherwise  disposed  under  them. 

As  we  have  shown  all  the  parts  of  the  perfect  insect 
contained  in  the  caterpillar,  so  these  can  be  much 
more  easily  exhibited  in  the  pupa,  particularly  when 
near  its  final  change;  for  in  more  early  periods  the 
substance  is  so  soft  and  pulpy  —  almost  fluid  indeed 
—  that  it  would  be  next  to  impossible  to  develop 
them  artificially.  In  some  pupa3  the  parts  can  even 
be  seen  through  the  membranous  envelope,  which  in 
other  cases  requires,  for  this  purpose,  to  be  removed. 
In  order  to  exhibit  this,  we  shall  select  a  few  instances 
in  which  the  facts  may  be  readily  verified,  by  those 
who  will  take  the  trouble  of  breeding  the  insects. 

The  first  we  shall  advert  to  is  that  of  the  chame- 

*  Goedart,  de  Inscctis,  77, 


292 


INSECT     TRANSFORMATIONS. 


leon  fly  (Stratiomys  chameleon),  whose  singular 
larva  we  formerly  described.*  When  this  draws  near 
the  period  of  its  transformation,  it  leaves  the  water, 
betaking  itself  to  the  adjacent  bank,  or  to  the  plants 
which  float  on  the  water,  creeping  up  so  as  to  leave 
only  a  part  of  its  tail  submersed.  In  this  position 
it.  remains,  contracting  itself  by  degrees  in  a  manner 
scarcely  perceivable,  and  losing  all  power  of  loco- 
motion. The  internal  portion  of  the  tail  at  the  same 
time  separates  gradually  and  insensibly  from  the 
exterior  skin,  becoming  greatly  contracted;  and,  ga- 
thering into  three  or  four  curvatures,  the  extremity  is 
thereby  left  empty.  Into  this  space  the  air  penetrates 
and  soon  fills  the  place  previously  occupied  by  the 
body,  which  is  now  contracted  to  one-third  of  its 
former  size.  When  the  air  is  prevented  by  too  much 


A,  Pupa  of  chameleon  fly,  with  the  lid  of  the  puparium  raised. 
B,  the  same  magnified,  and  the  puparium  laid  open  to  show  the 
embryo  fly.  C,  the  embryo  fly  magnified :  —  a  a,  antennae  ;  b  5, 
the  eyes;  r,  sucker;  d  rf,  first  pair  of  legs:  e  e,  second  pair ; 
//,  the  wings  folded  up  ;  g-  h  j,  rings  of  the  body  ;  k  k,  breath- 
ing-tubes. 

*  Page  156,  7. 


FORM    OF    PUP^E.  293 

moisture  from  entering  and  distending  the  skin,  it 
shrivels  up;  but  this  occurs  seldom.  If  the  old  skin, 
now  become  detached  and  forming  a  tubular  enve- 
lope, be  cut  open,  the  pupa  will  be  brought  into  view, 
exhibiting  the  parts  of  the  future  fly  neatly  folded 
down  upon  the  body,  as  may  be  seen  in  the  figure. 

This  is  one  of  the  larvae  which  Swammerdam  ob- 
served to  cast,  along  with  its  external  skin,  the  lining 
of  the  intestines,  and  breathing-tubes  likewise,  which, 
he  remarks,  *  is  very  singular,  and  amazingly  shows 
the  miracles  of  God,  teaching  at  the  same  time  how 
the  former  body  is  entirely  cast  off  and  renewed .'* 
The  pupa,  when  exposed  in  the  preceding  manner,  is 
of  a  bright  green  colour,  interspersed  with  white 
transparent  particles,  and  the  spiracles  of  the  wind- 
pipe glittering  like  pearls. 

When  the  pupa  of  the  lappit  moth  (Gastropacha 
quercifolia)  is  disengaged  from  the  cocoon,  it  has 
much  the  appearance  of  an  Egyptian  mummy,  or  an 
infant  in  the  old-fashioned  swaddling  bands.  The 
feet  are  crossed  over  the  breast,  and  folded  closely 
down  nearly  in  the  same  manner  as  in  the  instance 
of  the  chameleon  fly  just  mentioned;  but  the  wings 
are  compressed  into  a  very  small  compass.  This 
appears  the  more  remarkable  as  the  wings  of  the 
moth  are  large  and  conspicuous,  and  so  like  the 
withered  leaf  of  an  oak,  both  in  form  and  colour,  that 
the  insect  would  readily  impose  upon  a  careless 
observer.  It  is,  we  believe,  the  only  British  example 
of  what  have  been  popularly  termed  leaf  insects,  — 
which  have  given  origin  to  the  fanciful  and  untenable 
theory  of  intentional  deception  oh  the  part  of  Provi- 
dence. It  was  by  opening  one  of  these  pupso  that 
Heaumur  first  discovered  the  various  sheaths  appro- 
priated to  the  feet,  the  antennae,  and  the  wings;  the 
sheath  of  the  sucker  (haustellum)  being  wanting,  as  it 

*  Bibl.  Nat.  vol.  ii,  p.  5-1 
VOL,  vi.  25* 


294 


INSECT    TRANSFORMATIONS. 


is  obsolescent  in  the  moth.  It  is  furnished,  however, 
with  a  peculiar  horn  or  projection  on  the  forehead, 
—  the  palpi  —  which  the  theorists  to  whom  we  have 
alluded  might  term  its  leafstalk. 


a,  Pupa  of  lappit  moth.    6,  under  side  of  the  moth,  with  its 
feet  folded  up.    c,  side  view  of  the  same. 

We  can  demonstrate  the  same  position  still  more 
obviously  in  the  chrysalis  of  a  butterfly, — for  ex- 
ample, in  that  of  the  peacock  (  Vanessa  70),  whose  ca- 
terpillars feed  on  the  nettle.  This  chrysalis  is  an- 
gular like  the  others  of  the  genus,  —  the  two  termi- 
nating angles  encasing  the  eyes,  and  the  four  lateral 
ones  the  marginal  folds  of  the  wings,  the  contour  of 
which  is  disposed  on  what  may  be  called  the  shoulder 
of  the  chrysalis  (Ptero-theca,  KIRBY).  The  legs,  an- 
tennae, arid  sucker,  are  folded  down  longitudinally 
upon  the  breast,  very  similarly  to  what  occurs  in  the 
moth  just  described.  When  the  membranous  cover- 
ing, which  is  thinner  but  more  firm  and  elastic  than 
Indian  paper,  has  been  carefully  removed,  —  selecting 
for  this  operation  an  advanced  period  of  the  chrysalis, 
—  the  several  members  of  the  butterfly  may  be  seen 


STRUCTURE    OF    PUPJE. 


295 


folded  up  in  the  manner  we  have  here  indicated. 
The  wings  are  still  covered  with  moisture,  so  that  the 
powdery  down  which  clothes  them  is  scarcely  visible, 
and  they  have  not  yet  assumed  their  beautiful  colours 
and  elegant  markings,  but  are  of  a  dusky  ash-gray. 
The  legs,  however,  are  already  so  firm  that  the  insect 
moves  them  about,  and  also  coils  up  its  sucker,  and 
plays  its  antennae.  It  is  worthy  of  remark,  that  the 


a,  under  side  of  the  chrysalis  of  the  peacock  butterfly.  &,  the 
winjjs  and  antennae  triced  out  from  the  same,  r,  the  perfect  in- 
scvt  (Faneata  lo)  fully  developed. 


296  INSECT    TRANSFORMATIONS. 

membrane  which  covers  the  more  prominently  exposed 
parts,  such  as  the  legs,  is  considerably  thicker  than  the 
other  portions.*  Our  description  will  be  rendered 
more  intelligible  by  the  preceding  figures. 

It  will  obviously  appear  from  these  details,  in  what 
manner  superficial  observations  led  to  the  fancy  of 
one  insect  being  on  a  sudden  miraculously  metamor- 
phosed -or  transmuted  into  another.  Those,  indeed, 
who  persuaded  themselves  that  a  morsel  of  tainted 
beef,  or  a  bit  of  rotten  wood,  could,  by  some  inexpli- 
cable chemistry,  grow  into  limbs,  wings,  eyes,  and  all 
the  other  parts  of  an  insect,  with  its  admirable  orga- 
nization of  muscles,  nerves,  and  digestive  apparatus, 
had  no  difficulty  to  overcome  in  believing  that  the 
green  pulpy  mass  of  a  chrysalis  could  be  transmuted 
into  the  light  airy  wings  of  a  butterfly :  —  nay,  they  con- 
sidered the  matter  as  proved,  and  admired  the  sup- 
posed metamorphosis,  without  giving  themselves  the 
trouble  of  investigating  whether  it  was  real  or  possi- 
ble. *(*  Accurate  observation,  founded  on  the  princi- 
ples of  the  Baconian  philosophy,  gradually  put  to 
flight  the  reveries  of  those  who  (to  use  the  words  of 
Harvey)  '  philosophize  by  traduction,  who  are  not  a 
whit  wiser  than  the  inanimate  books  through  which 
they  come  at  their  ill-digested  notions.  'J  Yet  this 
distinguished  physiologist,  though  he  could  so  express 
himself,  occasionally  struck  upon  the  very  sand-bank 
of  which  he  here  warns  us  to  take  care;  perhaps  in 
consequence  of  a  cause  shrewdly  and  profoundly 
assigned  for  philosophical  errors  by  Des  Cartes,  in 
his  Essay  on  Method,  who  says, (  I  was  always  of 
opinion,  that  more  truth  is  to  be  found  in  those 
reasonings  which  men  make  use  of  in  the  common 
affairs  of  life,  whose  bad  success  may  prove  a  kind  of 
punishment  for  their  reasoning  ill,  than  those  which 

*  Swamraerdam,  vol.  ii,  p.  17. 
t  Reaumur,  vol.  i,  p.  350.      t  Harvey,  De  Gen.  An.,  Exer-  44. 


STRUCTURE    OF    PUP.K.  297 

some  idle  doctor,  cooped  up  in  his  study,  has  in- 
vented, that  conduce  nothing  to  the  ease  and  happi- 
ness of  life,  and  from  which  he  expects  no  other  ad- 
vantage unless  that  of  reaping  so  much  the  greater 
harvest  of  empty  glory  from  his  arguments;  as  they 
contain  less  of  truth  and  common  sense,  on  account 
of  the  extraordinary  strength  of  genius  and  applica- 
tion requisite  to  give  an  imposing  air  to  such  ab- 
surdities.7 

It  was  the  decided  opinion  of  Swammerdam  that 
the  several  transformations  of  insects,  particularly  the 
change  from  the  egg  to  the  caterpillar,  and  from  the 
pupa  to  the  perfect  insect,  are  chiefly  effected  by  the 
evaporation  of  the  superabundant  fluids.  Thus  he 
tells  us  that  the  nit,  or  egg  of  the  louse  (Pediculus 
humanus),  is  nothing  mare  than  the  insect  itself, 
which  only  requires  the  evaporation  of  the  surround- 
ing moisture  and  the  casting  of  the  old  skin,  to  bring 
it  to  its  perfect  form.*  It  is  not  a  little  surprising 
that  so  very  accurate  a  naturalist  should  never  have 
thought  of  investigating  the  truth  of  such  an  opinion 
by  experiment.  That  he  neglected  this  precaution,  is 
an  instance,  among  thousands  more,  of  the  imperfec- 
tion of  human  studies;  for  his  very  first  trial  would 
have  demonstrated  the  error,  which  pervades  every 
page  of  his  great  work.  He  was  evidently  misled 
into  the  opinion  by  perceiving  how  fluid  the  contents 
of  an  egg  or  of  a  pupa  are  when  opened  previous  to 
their  change,  and  how  dry  the  insect  is  upon  its 
evolution. 

It  is  much  more  surprising  to  find  Kirby  and 
Spence  repeating  the  same,  or  nearly  the  same  opi- 
nion, at  the  very  time,  too,  when  they  are  in  the  act 
of  quoting  the  experiments  of  Reaumur,  by  which  it 
is  refuted,  though  the  great  experimenter  himself  mis- 
interpreted them.  ( If  you  open  a  pupa,'  say  they, 

*  Swammerdam,  passim. 


298  INSECT    TRANSFORMATIONS. 

c  soon  after  its  assumption  of  that  state,  you  will  find 
its  interior  filled  with  a  milky  fluid,  in  the  midst  of 
which  the  rudiments  of  its  future  limbs  and  organs, 
themselves  almost  as  fluid,  swim.  Now  the  end  to 
be  accomplished  during  the  pupa's  existence  is,  the 
gradual  evaporation  of  the  watery  parts  of  this  fluid, 
and  the  development  of  the  organs  of  the  enclosed 
animal  by  the  absorption  and  assimilation  of  the  resi- 
duum.'* The  evaporation,  however,  is  so  very 
inconsiderable,  that  it  is  evidently  only  of  secondary 
consequence. 

When  the  great  quantity  of  fluid  in  the  body  of  the 
chrysalis  is  taken  into  consideration,  we  must  infer 
that  if  it  were  evaporated  to  any  extent,  the  insect 
would  be  reduced  to  a  mere  shadow.  We  are  dis- 
posed, therefore,  to  agree  with  Reaumur  in  thinking 
it  more  probable  that  the  fluids  of  pupae  become 
united  to  the  more  solid  parts,  in  the  same  way 
as  the  blood  and  lymph  in  our  own  bodies  go 
to  the  extension  or  to  the  repair  of  our  bones  and 
muscles.  To  put  this  to  the  test  of  experiment, 
Reaumur,  in  the  month  of  July,  accurately  weighed 
two  chrysalides  the  instant  they  were  disencumbered 
of  the  sloughs  of  the  larvae.  The  lightest  weighed  a 
trifle  less  than  18,  and  the  heavier  a  trifle  less  than 
19  grains.  Putting  them  aside  separately,  with  a 
note  of  their  respective  weights,  he  re-weighed  them 
every  two  or  three  days  for  sixteen  days  successively, 
that  is,  till  they  were  transformed  into  perfect  insects. 
On  the  last  day,  the  lighter  weighed  more  than  17, 
and  the  heavier  more  than  18  grains;  consequently 
the  fluid  evaporated  during  this  period  did  not  amount 
to  a  grain,  perhaps  not  to  more  than  i  of  a  grain.  On 
weighing  the  insects  themselves  which  issued  from 
these  pupa,  together  with  the  cast  slough,  the  weight 
was  not  sensibly  different.  The  fluid,  therefore, 

*  Introd.  iii,  262. 


STRUCTURE    OF    PUP.E.  299 

which  escapes  by  what  is  termed  insensible  perspi- 
ration, is  not  so  great  as  might  have  been  supposed. 
To  ascertain  what  it  was,  Reaumur  enclosed  several 
chrysalides,  whose  envelope  seemed  very  dry,  in  se- 
parate glass  tubes,  terminating  at  one  end  in  a  bulb, 
and  at  the  other  hermetically  sealed.  He  kept  these 
in  a  temperature  of  from  14°  to  15°  of  his  own 
thermometer,  corresponding  to  63°  —  65°  Fahr. ;  and 
in  a  few  days  minute  drops  of  water  appeared  on  the 
sides  of  the  tube,  which  rolled  down  into  the  bulb 
in  form  of  a  large  drop  —  not  *  eight  or  ten  large 
drops,'  as  Kirby  and  Spence,  by  some  oversight, 
have  stated.* 

It  would  certainly  be  considered  a  strange  and 
untenable  doctrine  to  maintain  that  it  is  the  evapo- 
ration produced  from  the  egg  by  the  heat  of  the  in- 
cubating mother,  which  causes  the  development  of 
the  chick  in  the  egg  ;  yet  this  is  precisely  similar  to 
what  is  maintained  by  Swammerdam,  Kirby,  and 
Spence,  —  the  chief  difference  being,  as  Reaumur  ob- 
seves,  that  the  chick  has  obvious  organs  for  appro- 
priating the  nutriment  contained  in  the  egg,  while  the 
insect  in  the  pupa  is  surrounded,  and,  as  it  were, 
bathed  by  the  fluid,  whose  passage  into  the  interior 
vessels  we  cannot  trace  by  the  eye.j"  That  they  do 
find  their  way  thither,  the  experiments  above  recorded 
unanswerably  demonstrate. 

The  pupaB  of  insects,  though  they,  in  most  in- 
stances, cease  from  locomotion,  and  appear  torpid, 
are  by  no  means  really  so;  for  it  would  be  no  less 
incorrect  to  look  upon  them  in  such  a  light,  than  to 
consider  an  ox  torpid  when  reclining  in  a  meadow  to 
ruminate  and  digest  the  grass  he  had  just  been  de- 

*  R/aumur,  vol.  i,  p.  373,  *  Unegouttc  beaucoup  plus  gros- 
se ;'  and  Kirby  and  Spence,  Intro,  lii,  262. 
f  Mem.  vol.  i,  p.  362,  &c. 


300 


INSECT    TRANSFORMATIONS. 


vouring.  This  is,  in  fact,  the  nearest  analogy  which 
occurs  to  us  among  the  other  classes  of  animals; 
for  the  pupa,  though  it  does  not  chew  the  cud  like 
the  ox,  assuredly  rests  for  the  purpose  of  digesting  or 
(if  the  term  be  preferred)  of  assimilating  the  cruder 
fluids  stored  up  by  the  caterpillar,  and  forming  or 
perfecting  therefrom  the  organs  and  members  of  the 
mature  insect.* 

Some  pupae  have  a  slight  motion,  particularly  of 
the  lower  parts  of  the  body,  and  a  few  others  differ 
little  from  the  perfect  insect,  continuing  to  move  and 
feed  ;  but  the  greater  number  remain  apparently  mo- 
tionless. That  they  have  internal  though  impercep- 
tible motions,  however,  is  proved  by  their  possessing 
similar  organs  of  respiration  with  caterpillars  and 
pefect  insects.  We  have  adverted,  in  a  former  page, 
to  the  eighteen  spiracles  which  communicate  with 
the  double  windpipe  of  caterpillars,  and  the  same  ap- 
paratus is  always  found  in  chrysalides,  situated  on 
the  sides  of  the  abdominal  rings.  This  we  think 
might  have  convinced  such  distinguished  observers 
as  Lyonnet  andMuschenbrok,  that  the  most  quiescent 
pupae  could  not  exist  without  breathing. 


«r,  Chrysalis  of  Gonepteryx  Rhamni.    6,  pupa  of  Laria  feucelina. 
c}  pupa  of  Sphinx  Ligustri. 

*  J.  R. 


STRUCTURE  OF  PUP^.  301 

Reaumur  and  De  Geer  proved  this  position  by 
numerous  experiments.  When  a  chrysalis,  for  in- 
stance, is  suspended  by  a  thread  and  immersed  in  oil 
up  to  the  tip  of  the  wing-cases,  it  does  not  seem  to 
be  much  injured,  and  the  perfect  insect  is  disclosed 
in  due  time.  If  respiration,  therefore,  be  essential  to 
the  life  of  the  chrysalis,  it  appears  as  if  it  could  exist 
with  at  least  the  greater  number  of  its  spiracles  ob- 
structed ;  but  this  does  not  happen  with  a  chrysalis 
just  formed,  which  always  dies.  JBy  immersing  the 
whole  chrysalis  in  oil,  it  is  certainly  killed;  and  even 
by  immersing  its  head  downwards  as  far  as  the  first 
pair  of  spiracles  situated  near  the  head.  This  seems 
to  indicate  accordingly  that  this  first  pair  is  more  es- 
sential to  the  insect  than  all  the  rest;  and  in  other  ex- 
periments it  is  also  found  to  emit  a  much  greater 
quantity  of  air  by  this  first  pair.  It  seems  of  much 
importance  in  such  experiments  to  attend  to  the  age 
of  the  pupa;  for  when  near  the  change  the  function 
of  respiration  is  carried  on  more  feebly,  and  at  length 
nearly  ceases. 

Besides  the  decisive  experiments  of  immersion  in 
oil,  Reaumur  placed  pupa3  of  various  species  in  the 
exhausted  receiver  of  an  air-pump,  and  at  every 
fresh  stroke  of  the  piston  their  bodies  both  bulged 
out  and  became  elongated :  because,  as  he  inferred, 
the  envelope  is  not  pervious  to  the  air  contained  in 
the  body,  and  the  spiracles  do  not  allow  of  its  escape 
with  sufficient  rapidity  to  keep  pace  with  the  ex- 
haustion of  the  receiver; — contrary  to  what  happens 
when  caterpillars  are  subjected  to  the  same  circum- 
stances. Varying  his  experiments,  he  placed  in  the 
exhausted  receiver  a  vessel  containing  water  deprived 
of  its  air,  and  in  this  plunged  a  chrysalis,  keeping 
it  immersed  by  means  of  a  weight  attached  by  a 
thread.  At  the  two  or  three  first  strokes  of  the  pis- 
ton, bubbles  of  air  appeared  at  each  of  the  spiracles., 

VOL.  vi.  26 


302  INSECT    TRANSFORMATIONS. 

issuing  by  jets,  and  a  few  smaller  bubbles  over  the 
body  of  the  chrysalis,  probably  from  not  taking  the 
precaution  afterwards  suggested  by  Bonnet,  of 
moistening  it  before  immersion.* 

Upon  examining  the  structure  of  the  spiracles, 
M.  Reaumur  farther  discovered  that  their  mouths  are 
furnished  with  ciliary  valves,  which  are  shut  when 
the  pupa  is  plunged  into  water,  but  opened  again 
when  it  is  taken  out.  This  circumstance  accounts 
for  the  swelling  of  the  body  under  the  exhausted 
receiver  of  the  air-pump,  for  it  may  be  supposed  the 
animal  would  closely  shut  the  valves  when  it  felt  the 
air  forcibly  extracted  from  its  body.  It  is  remarkable, 
however,  that  though  the  shutting  of  the  valves  pre- 
vents the  entrance  of  water,  it  has  not  the  power  of 
excluding  oil ;  because,  as  Reaumur  conjectures, 
it  is  not  in  the  ordinary  course  of  its  nature  exposed 
to  such  an  accident,  and  therefore  Providence  made 
no  provision  for  it.t  It  may  be  recollected  that  the 
larvas  of  the  cheese-fly  and  of  blow-flies  are  provided 
with  a  sort  of  valve  with  which  they  can  cover  such 
of  their  spiracles  as  become  immersed  in  any  greasy 
matter.  J 


a  b 

Spiracles  of  pupae,    a,  the  valve  open  ;    6,  the  same  shut. 

In  the   aquatic  pupa  of  the  ringed    China-mark- 
moth  (Hydrocampa  stratiotata,  STEPHENS)  De  Geer 

*  Bonnet,  GEuvres,  vol.  iii,  p.  39,  &c.       t  Mern.  i,  407,  <Src. 
t  See  page  265. 


STRUCTURE    OF    PUPJE.  303 

found  three  pairs  of  conspicuous  spiracles,  occupying 
the  second,  third,  and  fourth  rings,  and  placed  on 
cylindrical  tubes.  It  is  worthy  of  remark,  that  the 
caterpillar  spins  a  double  cocoon,  the  outer  of  a  thin, 
and  the  inner  of  a  close  texture;  and  when  the  respi- 
ratory gills  of  the  larva  are  cast  off  with  the  old 
skin,  the  insect  knows  how  to  surround  itself  with  an 
atmosphere  of  air  in  the  midst  of  the  water  where  it 
resides,  the  inner  cocoon  being  impervious  to  moisture. 
How  it  contrives  to  renew  this  air  when  vitiated  is 
not  yet  known,  but  that  it  derives  it  from  the  water 
is  proved  by  its  always  dying  if  removed  into  the 
air.* 

We  have  formerly  described  .the  beautiful  appara- 
tus for  respiration  in  the  Iarva3  of  the  gnat  family 
Culicidce,  LATR.);|  but  this  is  rivalled  by  the  organs 
destined  for  the  same  purpose  in  their  pupae,  which 
organs  are  situated  in  the  head  instead  of  the  tail. 
The  pupa,  in  the  same  way,  changes  its  position  in  the 
water,  swimming  with  its  head  upwards  instead  of 
downwards  as  before.  To  enable  it  to  maintain  this 
position,  the  pupa  is  farther  provided  with  a  fin-tail,  like 
a  fish,  by  which  it  can  move  itself  at  pleasure  in  the 
water.  It  no  longer,  indeed,  requires  to  take  food,  but 
air  is  indispensable  to  it;,  and  water  being  so  unstable, 
were  the  pupa  incapable  of  swimming,  it  would  seldom 
escape  being  drowned.  Its  respiratory  apparatus 
consists  of  two  tubes,  situated  behind  the  head,  on 
what  may  be  called  the  shoulders.  They  are  of  a 
funnel  shape,  and  project  very  sensibly,  though  we 
should  not  be  disposed  to  compare  them,  as  Reaumur 
does,  to  asses'  ears.  The  transparency  of  this  pupa 
renders  it  easy  to  see  in  it  the  parts  of  the  gnat. 

An  apparently  more  simple,  though  no  less  remark- 
able, apparatus  for  respiration,  was  observed  by 
Reaumur  in  the  pupa  of  a  small  crane  fly  (Tipula, 

*  De  Geer,  Mem,  i,  531.  t  See  page  156.. 


304 


INSECT    TRANSFORMATIONS. 


).     This  consisted  in  a  single  tube,  two  or 

three  times  longer  than  the  body  of  the  pupa,  and  as 
fine  as  a  hair.  The  point  of  this  hair  always  remains 
above  or  at  the  surface  of  the  water,  for  the  purpose 
of  carrying  on  respiration,  till  the  perfect  fly  is  ready 
to  emerge  from  the  water. 


6,  telescopic-tailed  pupa    of  the    same. 

c,  front  view  of  the  pupa  of  the  common  gnat  (Culex  pipiens.) 

d,  side  view  of  the  same. 

v  In  another  genus  of  this  family  the  external  organs 
of  respiration  are  very  elegant  in  form,  resembling 
more  the  fibrillae  of  minute  aquatic  mosses  (Con- 
fervoidece}  than  the  appendages  of  an  animal.  The 
larva  of  this  insect  is  well  known  to  anglers,  under 
the  name  of  the  bloodworm;  though  we  do  not  find 
it  mentioned  by  Walton,  Brookes,  Best,  Sir  H.  Davy, 
or  any  of  the  other  writers  upon  angling.  It  is 
usually  less  than  half  an  inch  long,  flat,  and  jointed 
like  the  wire  worm,  with  several  small  appendages  at 
the  tail,  which  appear  to  be  breathing-tubes,  of  the 


STRUCTURE    OF 


305 


nature  of  gills;  for  the  larva  lives  under  water  in  streams 
and  ditches,  enclosed  for  the  most  part  in  a  tube  of  earth. 
It  is  of  a  fine  crimson  colour,  the  origin  of  its  popular 
name;  but  it  becomes  more  dark  and  opaquein  the  pupa 
state. 

The  appendages  which  are  thrown  off  by  the  larva 


a,  Chironomus  ptuvwsus.    5,  larva  of  the  same,  called  the  Blood  worm, 
d,  pupae  of  ihe  same,  magnified  to  show  their  plumed  spiracles. 

VOL.  vi.  26* 


306  INSECT    TRANSFORMATIONS. 

are  replaced  by  a  brush-like  bunch  of  bristles,  the 
points  of  which,  it  is  probable,  have  the  power  of 
extracting  air  from  the  water;  and  a  similar  coronet  is 
produced  on  each  side  of  the  head,  disposed  in  a  five- 
rayed  star  of  plumes.  It  is  not  a  little  remarkable, 
that  a  double  envelope  for  the  feet  projects  from  each 
side  of  the  breast,  a  circumstance  which  seems  pecu- 
liar to  this  insect.  In  a  few  days  it  is  transformed  into 
a  pretty  gnat,  with  feathered  antennaB  (Chironomus 
plumosus,  MEIGEN). 

Such  are  a  few  examples  of  the  beautiful  contriv- 
ances for  carrying  on  the  important  process  of  respira- 
tion in  that  stage  of  life  during  which  few  insects  take 
any  food.  Considering  the  great  difficulties  presented 
to  us  in  the  investigation  of  this  subject,  we  may  well 
wonder  that  experiments  have  elucidated  and  proved 
so  many  facts.  We  are  still  ignorant,  however,  of  the 
nature  of  the  effects  produced  by  respiration  on  the 
fluids  of  pupae. 


CHAPTER  XIII. 

Transformation  of  Pup»  into  perfect  insects. 

THE  period  which  pupae  require  to  come  to  matur- 
ity seems  to  depend  mainly  on  temperature  and  size, 
though  there  are  several  other  causes  at  work  appa- 
rently inscrutable  to  human  research.  Those  who 
adopt,  after  Swammerdam,  the  untenable  theory  of 
evaporation  being  all  that  is  requisite  to  bring  an  insect 
to  maturity,  tell  us  that  these  two  circumstances  will 
account  for  all  the  phenomena;  but  we  shall  immedi- 
ately have  to  record  several  curious  facts  quite  at  vari- 
ance with  such  a  conclusion.  c  It  is  plain,'  say  Kirby 
and  Sperice,  *  that  this  necessary  transpiration,  other 
circumstances  being  alike,  must  take  place  sooner  in 
a  small  than  in  a  large  pupa.  Since  the  more  speedy 
or  more  tardy  evaporation  of  fluids  depends  upon  their 
exposure  to  a  greater  or  less  degree  of  heat,  we  might, 
a  priori,  conclude  that  pupae  exposed  to  a  high  tem- 
perature would  sooner  attain  maturity,  even  though 
larger  in  bulk,  than  others  exposed  to  a  low  one:  and 
this  is  the  fact.  The  pupa  of  a  large  moth,  which  has 
assumed  that  state  in  th§  early  part  of  summer,  will 
often  disclose  the  perfect  insect  in  twelve  or  fourteen 
days;  while  that  of  an  ichneumon,  not  one-hundredth 
part  of  its  size,  that  did  not  enter  this  state  till  late  in 
autumn,  will  not  appear  as  a  fly  for  seven  or  eight 
months.  But  this  is  not  the  whole.  The  very  same 
insect,  according  as  it  has  become  a  pupa  at  an  earlier 
or  a  later  period  of  the  year,  will  at  one  time  live  but 


308  INSECT    TRANSFORMATIONS. 

a    few   weeks,    at    another   several   months   in    that 
state.'* 

But  though  we  admit  all  these  facts,  which  are 
known  to  every  naturalist,  and  too  well  ascertained  to 
be  denied,  we  submit  that  the  inference  of  evaporation 
being  the  exclusive  effect,  is,  upon  the  whole,  inad- 
missible. Reaumur,  though  he  does  not  absolutely 
state  his  belief  in  such  an  inference,  shows  by  his  rea- 
soning that  he  was  strongly  disposed  to  adopt  notions 
closely  bordering  upon  it.  The  theoretical  doctrine, 
it  may  be  perceived,  takes  for  granted  that  evapora- 
tion is  the  only  result  of  heat ;  overlooking  the  no  less 
obvious  effect  of  expansion,  besides  the  disposition  it 
produces  in  chemical  principles  to  combine  or  be  de- 
composed. But  these  are  only  some  of  its  inanimate 
results,  which  would  occur  upon  material  objects  inde- 
pendently of  life;  whereas  in  living  bodies,  what  may 
be  called  chemical  changes  are  frequently  very  differ- 
ent from  what  can  be  effected  out  of  the  living  body, 
and  consequently  we  cannot  trace  all  the  effects  pro- 
duced by  heat  in  the  two  great  internal  processes  of 
secretion  and  consolidation.  In  detailing,  therefore, 
the  interesting  experiments  of  Reaumur  on  pupa?,  which 
he  subjected  to  different  degrees  of  heat  and  cold,  we 
shall  not  adopt  his  inferences  respecting  evaporation 
The  accuracy  of  the  experiments  themselves  is  un 
questionable. 

Reasoning  from  some  of  the  facts  above  stated, 
Rfaumur  thought  it  might  be  possible  to  hasten  or 
retard  the  exclusion  of  insects  from  their  pupa?,  in 
the  same  way  as  some  flowers  are  forced  to  blow 
early,  and  others  kept  back  Trom  blowing  at  their  due 
season;  and  he  commenced  a  series  of  experiments  to 
ascertain  the  facts.  In  January  1734,  he  accordingly 
placed  a  great  number  of  the  chrysalides  of  moths 
and  butterflies  of  various  species  in  one  of  the  royal 

*  Intr.  iii,  263. 


EXPERIMENTS    ON    INSECTS.  309 

hot-houses  at  Paris.  His  success  was  equal  to  his 
expectations,  for  the  insects  appeared  in  the  middle 
of  winter,  some  in  ten  or  twelve  days,  and  others  in 
from  three  to  six  weeks  from  the  time  of  their  removal 
into  a  warmer  atmosphere.  Five  or  six  days,  indeed, 
seemed  to  be  equal  to  a  month  of  natural  temperature. 
A  week  was  even  equal  to  a  month  for  the  chrysalides 
which  naturally  required  the  temperature  of  mid- 
summer to  bring  them  to  maturity  ;  because  the  arti- 
ficial temperature  was  both  high  and  more  uniform, 
particularly  during  the  night.  The  butterflies  and 
moths  thus  forced  into  premature  appearance,  were 
equally  full  grown,  healthy  and  lively,  with  those 
produced  in  the  usual  way  ;  and  the  females  deposited 
their  eggs  and  soon  afterwards  died,  as  they  always 
do  in  summer  in  the  open  fields.  The  life  of  these 
insects  was,  therefore,  shortened  by  some  months. 

The  following  November,  Reaumur  tried  a  similar 
experiment,  which  was  consequently  begun  two 
months  earlier  than  the  former  ;  and  the  insects  were 
also  evolved  proportionally  sooner.  Those,  for  ex- 
ample, which  ought  naturally  to  have  appeared  in 
May,  he  obtained  in  December.  In  butterflies  which 
have  a  double  brood,  such  experiments  become  still 
more  interesting  to  the  physiologist.  The  beautiful 
swallow-tailed  butterfly  (Papilio  Machaon)  is  one  of 
those  which  are  double  brooded,  the  first  going  into 
chrysalis  in  July,  and  the  butterfly  appearing  in 
thirteen  days  ;  —  the  second,  in  the  autumn,  and  the 
butterfly  not  appearing  till  the  succeeding  June.  But 
if  placed  in  an  artificial  temperature  of  due  warmth, 
and  properly  regulated,  the  second  brood  will  appear 
in  about  the  same  time  as  the  first. 

Reaumur  tried  some  experiments,  still  more  inge- 
nious, with  chrysalides,  which  were  suggested  by  the 
effects  produced  by  birds  sitting  upon  their  eggs  in 
order  to  hatch  them,  He  concluded,  that  if  chry- 


310  INSECT    TRANSFORMATIONS. 

salides  were  placed  under  a  sitting  bird,  they  would 
be  matured  in  a  similar  way  as  he  had  found  them 
to  be  in  the  green-house.  The  difficulty  was  to  pre- 
vent them  from  being  bruised  and  crushed  by  the 
bird,  as  they  are  much  softer  and  more  easily  injured 
than  eggs.  This  he  obviated  by  enclosing  them  in 
hollow  glass  balls  about  the  size  of  a  hen's  egg,  which 
at  the  same  time  as  readily  deceived  the  bird  as  a  piece 
of  chalk  passes  with  the  eggs  set  to  hatch  under  a  hen. 
The  chrysalides  which  he  first  tried  were  those  of  the 
small  tortoiseshell  butterfly  (Vanessa  Urticce),  eight 
of  which,  attached  to  square  pieces  of  paper,  were  sus- 
pended within  the  glass  egg  as  near  to  each  other  as 
possible,  and  placed  under  a  hen  on  the  22d  of  June. 
The  aperture  of  the  glass  egg  was  closed,  but  in  such 
a  manner  as  to  leave  a  communication  with  the  ex- 
ternal air.  The  effect  of  the  heat  manifested  itself 
the  first  day,  in  the  moisture  exhaled  from  the  chrysa- 
lides, all  the  interior  of  the  glass  being  covered  with 
minute  drops  of  water,  which  he  allowed  to  evaporate 
by  unstopping  the  glass,  lest  the  moisture  might  spoil 
his  experiment.  When  it  was  dry,  he  replaced  it 
under  the  hen,  and  he  observed  no  moisture  exhaled 
on  the  following  days,  the  chief  transpiration  having 
occurred  in  the  first  twenty-four  hours.  In  about 
four  days  the  first  butterfly  that,  perhaps,  was  ever 
hatched  under  a  hen  made  its  appearance.  He  found 
four  more  evolved  next  morning,  and  one  on  the  suc- 
ceeding day,  the  28th  of  June.  Those  of  the  same 
brood  which  were  contained  in  a  nurse-box  placed  in 
a  window,  did  not  appear  before  the  5th,  and  some 
not  before  the  8th  of  July,  which  was  ten  or  twelve 
days  later.  Two  out  of  eight  of  the  chrysalides  which 
had  been  enclosed  in  the  glass  egg  died.  He  made 
a  similar  experiment  with  the  same  success  upon 
several  chrysalides  of  the  peacock  butterfly  (  Vanessa 
Jo).  With  the  pupas  also  of  two-winged  flies  and 


EXPERIMENTS   ON    INSECTS.  311 

other  insects,  he  tried  all  the  preceding  experiments 
with  very  similar  results.  The  heat  communicated  to 
the  glass  egg  was  very  considerable,  amounting  to 
31°  or  32°  of  Reaumur's  thermometer,*  or  about  100° 
Fahr.  It  was  not  surprising,  therefore,  that  some  of 
the  pupae  perished  :  we  think  it  more  wonderful  that 
any  of  them  survived. 

Reaumur  suggests,  from  these  experiments,  that 
those  who  are  curious  in  obtaining  the  productions 
of  summer  during  winter,  may  add  to  the  gaiety 
of  their  forced  flowers,  by  forcing  a  brood  of  butter- 
flies into  life  to  sport  amongst  them  ;  and  he  records 
an  instance  in  which  a  friend  of  his  at  Strasburgh  in 
this  way  hatched,  by  means  of  a  stove,  all  the  pupas 
he  could  obtain.  We  have  in  several  instances  suc- 
ceeded in  obtaining  butterflies  in  winter,  by  keeping 
chrysalides  under  glasses  on  a  mantel-piece  in  a  room 
with  a  constant  fire;  but  during  the  winter  of  1829-30, 
all  which  were  thus  kept  died,  probably  from  the  fires 
required  by  the  unusual  severity  of  the  season  being 
too  great  for  them.  Several,  on  the  other  hand, 
which  we  found  on  walls,  and  which  had  been  ex- 
posed to  all  the  rigours  of  the  winter,  were  disclosed 
in  due  time  in  a  perfect  state. 

Having  thus  ascertained  that  heat  produced  the 
effects  which  he  had  anticipated,  Reaumur  next  tried  an 
opposite  series  of  experiments,  by  placing  chrysalides 
in  diminished  temperatures.  He  accordingly  en- 
closed in  nurse-boxes  a  number  of  pupae  formed  in 
August  1733,  and  in  the  following  January  placed 
them  in  a  coal-cellar  :  their  natural  period  of  appear- 
ing in  the  perfect  state  being  July  1734.  During  the 
hot  months  of  this  year  he  went  from  time  to  time  to 
see  whether  these  pupae  indicated  an  approaching 
change,  but  they  remained  in  their  original  state 
during  July  and  August,  and  continued  so  till  the  suc- 

f  Reaumur,  Mem.  vol.  ii,  p.  17. 


312  INSECT    TRANSFORMATIONS. 

ceeding  August,  1 735,  at  the  time  he  was  writing  this 
account,  when  he  found  them  still  living  and  healthy, 
but  not  transformed  into  perfect  insects.  We  are  not 
aware  whether  he  ever  published  the  termination  of 
the  experiment. 

In  another  instance,  he  placed  in  a  coal-cellar  the 
pupce  of  the  emperor  moth  (Saturnia  pavonia),  about 
a  fortnight  or  three  weeks  before  the  usual  time  of 
their  evolution;  and  they  were  in  consequence  retarded 
to  five  or  six  weeks  later  than  those  of  the  same 
brood  which  he  had  kept  in  his  cabinet.  The  chry- 
salides of  the  large  garden  white  butterfly  (Pontia 
Brassicce^y  when  placed  in  the  cellar  in  January, 
appeared  two  months  later  than  those  in  the  tem- 
perature of  the  atmosphere.  A  still  more  decisive 
experiment  was  made  with  the  chrysalides  of  the 
small  tortoiseshell  butterfly  (Vanessa  t/r/icce),  which 
require  fourteen  days  of  summer  heat  to  mature 
them,  and  which,  when  hatched  under  a  hen,  had 
appeared  in  four  days.  Some  of  these  he  placed  in 
the  cellar  the  12th  of  June,  and  they  did  not  appear 
till  the  2d  and  3d  of  August,  —  about  six  weeks  later 
than  in  their  natural  temperature. 

Reaumur,  still  haunted  by  the  notion  of  the  ex- 
halation of  moisture  being  the  only  cause  of  the 
development  of  chrysalides,  tried  upon  them  similar 
ingenious  experiments  to  those  which  he  had  success- 
fully made  upon  eggs,  by  varnishing  them  in  order  to 
prevent  the  escape  of  moisture.  His  experiments 
upon  varnishing  eggs  have  led  to  a  most  useful  dis- 
covery, now  extensively  acted  upon  in  practice  for 
the  preservation  of  eggs  all  over  Europe.  Those 
upon  chrysalides,  however,  were  not  conducted  with 
the  same  degree  of  acute  accuracy.  To  prevent  the 
chrysalides  from  coming  to  maturity  at  the  usual 
time,  by  preventing  the  exhalation  of  their  moisture, 
he  conceived  it  would  be  sufficient  to  varnish  over 


EXPERIMENTS  ON  INSECTS.  313 

the  envelope,  taking  care  to  leave  the  respiratory  spi- 
racles unobstructed.  But  it  is  most  obvious,  that  the 
greater  part  of  all  the  evaporation  which  occurs  must 
be  through  the  spiracles,  in  the  same  way  as  a  large 
proportion  of  the  moisture  of  the  human  body  passes 
off  by  the  breath.  The  result,  however,  of  Reau- 
mur's experiments  with  the  varnished  chrysalides  was, 
that  they  were  developed  several  weeks  later  than 
when  placed  in  their  natural  circumstances,  —  which 
proves,  we  think,  that  the  envelope  has  considerable 
influence  on  the  transforrnatory  process  going  on  in 
the  interior,  even  were  we  to  leave  the  transpiration  of 
moisture  out  of  the  question.* 

We  may  remark,  that  the  results  of  these  experi- 
ments afford  interesting  illustrations  of  the  torpidity  of 
both  the  larger  animals  and  of  plants.  In  the  United 
States  of  America,  for  example,  many  species  of  ani- 
mals which  become  torpid  in  Pennsylvania,  and  other 
more  northern  parts  of  the  country,  remain  lively  in 
the  Carolinas,  and  other  southern  parts  of  the  conti- 
nent. |  Mr  Gough  found  that  the  dormouse  may  be 
prevented  from  becoming  torpid  by  supplying  it  plen- 
tifully with  food;  and  Dr  Reeve,  of  Norwich,  ob- 
served the  same  circumstance  in  a  hedge-hog,  which 
being  kept  warm  and  well  fed,  showed  no  disposition 
to  become  torpid  even  during  severe  weather. J  Pal- 
las had  a  tame  marmot,  also,  which  having  become 
very  fat  during  the  summer,  showed  no  disposition  to 
torpidity,  though  exposed  to  a  temperature  which 
threw  the  whole  species  into  a  torpid  state  in  that  part 
of  Siberia.  In  the  vegetable  kingdom,  again,  it  is  a 
very  common  phenomenon  to  see  plants  revive  after 
exposure  to  severe  frosts.  Mr  Gough  made  some  in- 

*  Reaumur,  Mem.  vol.  ii.  p.  56. 
t  Barton,  in  Amer.  Phil,  Trans,  vol.  iv. 
$  Reeve  on  Torpidity,  p.  73. 
TOL.  vi.  27 


314  INSECT    TRANSFORMATIONS. 

genious  experiments  in  proof  of  this  upon  several 
plants,  such  as  the  small  duck's  meat  (Lemna  minor), 
and  the  viviparous  fescue  grass  (Festuca  vivipara), 
which  led  to  the  conclusion  that  they  could  accommo- 
date themselves  without  perishing  to  the  vicissitudes  of 
variable  situations.* 

We  observed  a  no  less  marked  instance  than  those 
recorded  by  Mr  Gough,  in  a  plant  of  the  geranium, 
named  Prince  Leopold  (Pelargonium  macranlhon^ 
SWEET),  the  whole  of  whose  leaves  were  so  hard  fro- 
zen as  to  break  rather  than  bend.  We  immersed  the 
whole  of  the  plant  in  cold  water,  a  few  degrees  above 
freezing,  till  it  was  thawed,  and  it  recovered  so  com- 
pletely, that  not  a  single  frosted  spot  appeared  on  any 
of  the  leaves. I 

Several  extraordinary  facts  relating  to  insects  prove 
that  temperature  alone  will  not  account  for  the  varia- 
tions of  the  periods  of  their  disclosure.  It  is  stated  by 
Marsham,  that  Mr  Jones  of  Chelsea,  in  one  of  his  ex- 
cursions, caught  a  female  of  the  spotted  muslin  moth 
(Diaphora  mendica,  STEPHENS),  which  laid  a  number 
of  eggs,  and  he  fed  thirty-six  of  the  caterpillars  hatch- 
ed from  these,  till  they  spun  their  cocoons  and  be- 
came pupae.  At  the  usual  season  only  a  third  of  these 
produced  moths,  and  he  concluded  the  rest  were  dead : 
but,  to  his  utter  astonishment,  twelve  more  made  their 
appearance  the  second  season;  and  the  remaining 
twelve  were  evolved  the  third  season,  as  perfect  and 
healthy  as  those  which  had  been  first  produced. J 

The  same  extraordinary  fact  has  been  observed  in 
the  pupa3  of  the  small  egger-moth  (Eriogaster  lanes- 
tris),  the  greater  number  of  those  which  spin  up 
in  summer  appearing  in  the  succeeding  February, 

*  Manchester  Trans,  t  J«  R- 

t  Linn,  Trans,  vol.  x,  p.  402. 


EXPERIMENTS    ON    INSECTS.  315 

but  others  of  them  requiring  two,  three,  and  even 
four,  years.*  Meinecken  kept  several  pupas  of  the 
emperor-moth  ( Saturnia  pavonia)  through  the  winter 
in  a  room  heated  daily  by  a  stove,  and  others  in  a  cold 
chamber.  Some  of  both  these  appeared  in  March, 
and  others,  though  evidently  healthy,  had  not  ap- 
peared in  July. J* 

It  is  certain,  however,  that  this  is  not  the  natural 
order  of  things,  even  in  this  species  ;  for  we  have 
reared  several  broods  of  the  species  respecting  which 
the  preceding  facts  are  recorded,  without  having 
observed  them.  In  a  large  brood  of  the  small  egger 
(Eriogaster  lanestris)  five  or  six  of  the  cocoons  did 
not  produce  insects,  and  we  consequently  anticipated 
their  appearance  next  year,  but  we  have  now  kept 
them  five  years  without  any  change,  and  therefore 
conclude  they  are  dead.J  The  inference  deduced, 
however,  from  the  facts  observed,  is  very  plausible, 
namely,  that  it  is  intended  by  Providence  to  preserve 
the  species  :  for  were  all  the  individuals  of  a  brood  to 
appear  in  the  same  season,  it  might  happen  to  be  so 
ungenial,  particularly  in  the  early  months  of  spring, 
as  to  destroy  them  before  they  could  deposit  their 
eggs;  whereas,  by  their  appearing  in  different  seasons, 
some  of  them  have  the  chance  of  coming  forth  in 
mild  weather.  §  Yet,  perhaps,  this  may  be  an  unne- 
cessary though  ingenious  refining  upon  a  final  cause  : 
for  even  in  the  most  ungenial  spring  weather,  there 
always  occur  some  fine  days,  and,  further,  a  brood  of 
insects  does  not  all  appear  on  one  day,  but  more  usually 
on  many  successive  days,  as  may  be  seen  by  the  experi- 
ments of  Reaumur  recorded  at  the  beginning  of  this 

*  Scriba,  Journ.  i,  vol.  iii,  p.  222  ;  and  Haworth,  Lepidopt. 
Brit,  vol.  i,  p.  125. 

t  Naturf.,  vol.  viii,  p.  143.  t   J.  R. 

§  Kirby  and  Spence,  vol.  iii,  p.  267. 


316  INSECT    TRANSFORMATIONS. 

chapter.  In  the  instance  of  the  clear  underwing 
(JEgema  asiliformis,  STEPHENS),  we  discovered  a 
brood  of  above  a  dozen  of  the  pupae  in  the  trunk  of  a 
black  poplar  ;  but  though,  from  feeding  on  the  wood 
of  the  tree,  the  caterpillars  must  have  been  well  pro- 
tected from  the  vicissitudes  of  the  seasons,  there  was 
nearly  a  month  between  the  appearance  of  the  first 
and  the  last.*  This,  indeed,  is  so  very  common  an 
occurrence  that  it  is  almost  superfluous  to  mention 
particular  instances. 

The  moths  just  mentioned,  we  may  remark,  were 
only  observed  to  appear  about  noon  ;.  and  many 
other  insects  are  known  to  emerge  from  the  pupa 
only  at  one  particular  time  of  the  day,  similar  to  the 
flowers,  such  as  the  goat's-beard  (Tragopogon],  and 
the  night-flowering  cereus  (Cactus  grandiflorus], 
which  only  blow  at  particular  hours.  Some  insects 
are  produced  at  sunrise,  others  at  noon,  and  others 
again  only  at  night.  Several  species  are  extremely 
regular  in  their  appearance,  such  as  the  orange-tip 
butterfly  (Pontia  Cardamines),  which  is  usually  seen 
about  the  end  of  April,  varying  bu.t  few  days  in  the 
course  of  many  years.  The  various  species,  also,  of 
May-flies  (Ephemerae}  are  confined  in  their  appear- 
ance to  two  or  three  days  ;  and  those  observed  by 
Reaumur  appear  at  no  other  time  than  between 
eight  or  ten  in  the  evening.  Those  which  we  no- 
ticed on  the  Rhine  in  August,  1829,  began  to 
appear  at  sunset,  and  before  morning  were  all  dead. 
In  the  great  square  at  Wiesbaden,  their  bodies  were 
so  thickly  strewn  about  that  it  seemed  as  if  a  shower 
of  snow  had  fallen  during  the  night,  their  wings 
being  white,  and  about  the  size  of  a  broad  snow- 
flake.t 

The  pupae  of  these  May-flies,  when  about  to  un 

*  J.  R.  t  J.  R, 


MODES    OF    EMERGING    FROM    PUPjE.  317 

dergo  their  transformation,  emerge  from  their  sub- 
aqueous galleries  and  come  to  the  surface  of  the 
water.  As  they  must  keep  their  wings  dry,  the  pro- 
cess would  appear  to  be  one  of  considerable  diffi- 
culty ;  yet  an  observer  may  remark  that  they  perform 
it  with  the  utmost  ease.  In  the  instance  of  the  gnat, 
this  process  of  emerging  from  the  water  is  still  more 
conspicuous  on  account  of  the  difference  of  form  in 
the  pupa  and  the  fly. 

About  eight  or  ten  days  after  the  larva  of  a  gnat  is 
transformed  into  a  pupa,  it  prepares,  generally  to- 
wards noon,  for  emerging  into  the  air,  raising  itself 
up  to  the  surface  so  as  to  elevate  its  shoulders  just 
above  the  level  of  the  water.  It  has  scarcely  got  into 
this  position  for  an  instant,  when,  by  swelling  the 
part  of  its  body  above  water,  the  skin  cracks  between 
the  two  breathing  tubes,  and  immediately  the  head  of 
the  gnat  makes  its  appearance  through  the  rent. 
The  shoulders  instantly  follow,  enlarging  the  breach 
so  as  to  render  the  extrication  of  the  body  compara- 
tively easy.  The  most  important  and  indeed  indis- 
pensable part  of  the  mechanism,  is  the  maintaining 
of  its  upright  position  so  as  not  to  get  wetted,  which 
would  spoil  its  wings  and  prevent  it  from  flying.  Its 
chief  support  is  the  rugocity  of  the  envelope  which  it 
is  throwing  off,  and  which  now  serves  it  as  a  life-boat 
till  it  gets  its  wings  set  at  liberty  and  trimmed  for 
flight.  The  body  of  the  insect  serves  this  little  boat 
for  a  mast,  which  is  raised  in  a  manner  similar  to 
moveable  masts  in  lighters  constructed  for  pass- 
ing under  a  bridge,  with  this  difference,  that  the 
gnat  raises  its  body  in  an  upright  direction  from  the 
first.  *  When  the  naturalist,'  says  Reaumur,  c  ob- 
serves how  deep  the  prow  of  the  tiny  boat  dips  into 
the  water,  he  becomes  anxious  for  the  fate  of  the 
little  mariner,  particularly  if  a  breeze  ripples  the 

VOL.  vi.  27* 


318  INSECT    TRANSFORMATIONS. 

surface,  for  the  least  agitation  of  the  air  will  waft  it 
rapidly  along,  since  its  body  performs  the  duty  of  a 
sail  as  well  as  of  a  mast  :  but  as  it  bears  a  much 
greater  proportion  to  the  little  bark  than  the  largest 
sail  does  to  a  ship,  it  appears  in  great  danger  of 
being  upset  ;  and  once  laid  on  its  side,  all  is  over. 
I  have  sometimes  seen  the  surface  of  the  water 
covered  with  the  bodies  of  gnats  which  had  perished 
in  this  way  ;  but  for  the  most  part  all  terminates 
favourably,  and  the  danger  is  instantly  over.'* 
When  the  gnat  has  extricated  itself  all  but  the  tail, 
it  first  stretches  out  its  two  fore-legs,|  and  then  the 
middle  pair,  bending  them  down  to  feel  for  the 
water,  upon  which  it  is  able  to  walk  as  upon  dry 
land,  the  only  aquatic  faculty  which  it  retains  after 
having  winged  its  way  above  the  element  where  it 


The  gnat  (Culex  pipitm")  escaping  from  the  pupa. 

*  Mem.,Tol.  iv,  p.  613. 

f  Kirby  and  Spence,  by  mistake,  say  it  '  draws*  these  e  out 
t)f  their  caseS  vol.  iii,  p.  288. 


MODES    OF    EMERGING    FROM    PUPJE.  319 

spent  the  first  stages  of  its  existence.  c  It  leaves, 
says  Swammerdam,  c  its  cast  skin  on  the  water 
where  it  insensibly  decays.'*  Reaumur  doubts 
whether  Swammerdam  ever  actually  saw  this  inte- 
resting transformation.  We  have  seen  it  twice  only. 
The  beautiful  pupa  formed  from  the  blood  worm, 
as  before  described,  proceeds  in  its  transformation 
much  in  the  same  way  as  the  common  gnat.  But 
how,  it  may  be  asked,  can  the  insect  raise  its 
shoulders  above  the  surface  of  the  water,  than  which 
it  is  specifically  heavier,  and  suspend  itself  there 
without  motion  ?  '  By  a  most  singular  and  beau- 
tiful contrivance,  which,'  says  Kirby,  c  I  shall  ex- 
plain, the  more  particularly  because  it  has  escaped 
Reaumur,  and,  as  far  as  I  know,  all  other  entomo- 
logical observers.  The  middle  of  the  back  of  the 
thorax  has  the  property  of  repelling  water,  appa- 
rently from  being  covered  with  some  oily  secretion. 
Hence,  as  soon  as  the  pupa  has  once  forced  this 
part  of  its  body  above  the  surface,  the  water  is  seen 
to  retreat  from  it  on  all  sides,  leaving  an  oval  space 
in  the  disk,  which  is  quite  dry.  Now  though  the 
specific  gravity  of  the  pupa  is  greater  than  that  of 
water,  it  is  but  so  very  slightly  greater,  that  the  mere 
attraction  of  the  air  to  the  dry  part  of  the  thorax, 
when  once  exposed  to  it,  is  sufficient  to  retain  it  at 
the  surface;  just  as  a  small  dry  needle  swims  under 
similar  circumstances.  That  this  is  a  true  solution 
of  the  phenomenon,  I  am  convinced  by  the  result  of 
several  experiments.  If,  when  the  pupa  is  sus- 
pended at  the  surface,  a  drop  of  water  be  let  fall 
upon  the  dry  portion  of  the  thorax,  it  instantly  sinks 
to  the  bottom,!  the  thorax,  which  belongs  to  the 
heaviest  half,  being  the  lowest;  and  if  the  pupa  be 

*  Part  i,  p.  156. 

•t  But,  if  so,  we  may  ask  what  has  become  of  the  power  of 
the  thorax  to  repel  water  ?     J.  R. 


320  INSECT   TRANSFORMATIONS. 

again  brought  to  the  surface,  so  that  the  fluid  is 
repelled  from  its  disk,  it  remains  there,  without 
effort,  as  before.  Just  before  the  exclusion  of  the 
fly  ( Chironomus  plumosus,  MEIGEN),  the  dry  part 
of  the  thorax  is  seen  to  split  in  the  middle.  The 
air  enters,  and  forms  a  brilliant  stratum,  resembling 
quicksilver,  between  the  body  of  the  insect  and  its 
puparium;  and  the  former  pushing  forth  its  head 
and  fore-legs,  like  the  gnat,  rests  the  latter  upon  the 
water,  and  in  a  few  seconds  extricates  itself  wholly 
from  its  envelope.'* 

The  grubs  of  several  of  the  four-winged  water 
flies  (Phryganidce,  STEPHENS),  popularly  called 
case  worms  and  caddis  worms,  construct  a  remark- 
able apparatus  for  protecting  the  pupa  during  its 
state  of  inactivity  and  helplessness.  So  long  as  it 
remains  in  the  grub  state  it  can  withdraw  itself  within 
its  case  of  shells,  stones,  or  reed-stems;  but  as  soon  as 
it  feels  its  change  approaching,  it  contrives  additional 
security.  It  weaves,  for  this  purpose,  at  the  entrance 
of  its  gallery,  a  grating  of  its  singular  silk,  which 
hardens  in  water  and  remains  indissoluble,  as  was 
first  observed  by  Vallisnieri.  The  strong  threads 
are  made  to  cross  each  other,  forming  a  small 
thickish  circular  plate  of  brown  silk,  which  becomes 
as  hard  as  gum,  fitting  exactly  into  the  opening, 
and  placed  a  little  within  the  margin.  One  of  these 
gratings  (described  by  De  Geerj  is  pierced  all  over 
with  holes,  disposed  in  concentric  circles,  separated 
by  ridges  running  from  the  centre  to  the  circum- 
ference, though  not  quite  so  regularly  as  the  spokes 
of  a  wheel  Other  ridges,  again,  are  made  to  tra- 
verse the  concentric  rays,  following  ihe  course  of  the 
circles  of  holes,  in  such  a  manner  as  to  form  com- 
partments, each  having  a  hole  in  its  centre. t  Reau- 
mur found  that  these  holes  were  for  the  purpose  of 

*  Tntr.,  iii,  p.  290.    t  De  Geer,  Mem.,  vol.  ii,  p.  519  —  45; 


MODES    OF    EMERGING    FROM    PUP.E.  321 

breathing,  by  admitting  a  current  of  fresh  water,  effect- 
ed, no  doubt,  by  the  spiracles  of  the  pupa;  and  he 
actually  saw  the  grate-work  in  alternate  motion  from 
convex  to  concave,  as  the  water  passed  out  and  in. 

Our  motive,  however,  for  introducing  a  notice  of 
these  structures  is  for  the  purpose  of  explaining  the 
contrivance  by  which  the  pupa  makes  its  exit  through 
the  grating.  To  effect  this,  it  is  provided  with  a  pair 
of  curved  mandibles,  which  appear  to  be  applied  to  no 
other  use,  for  they  are  thrown  off  upon  its  transform- 
ation into  a  fly,  as  was  observed  by  Vallisnieri.  These 
facts  may  be  verified  by  searching  for  caddis  worms 
during  the  early  spring  months,  as  most  of  them  are 
transformed  in  the  first  part  of  the  summer. 


c,  Pupa  of  a  case-fly  (Phryganea).     c  <Z,  grate-works  of  the 
same  at  the  openings  of  the  cases,  greatly  magnified.     6,  the  - 
perfect  insect. 

In  the  common  blow-fly  (Musca  carnaria*),  and 
many  of  the  same  family,  the  exit  of  the  perfect  insect 
from  the  pupa  case  is  effected  by  a  very  different,  but 
no  less  admirable  contrivance.  The  head  of  the  per- 
fect fly,  it  may  be  remarked,  is  hard  and  unyielding; 
but  in  the  pupa  it  is  soft,  and  capable  of  great  disten- 


322  INSECT    TRANSFORMATIONS. 

sion.  When  the  insect,  therefore,  becomes  desirous 
of  escaping  from  its  prison,  it  blows  out  the  extensile 
part  of  its  head  like  a  bladder,  alternately  pushing  it 
forward  in  the  form  of  a  muzzle,  and  swelling  it  out 
at  the  sides  in  the  form  of  a  ball,  till  it  succeeds  in 
rupturing  the  pupa  case.  As  this  envelope  is  too 
opaque  to  see  the  process  distinctly  on  the  outside,  it 
is  necessary  to  open  the  pupa  just  before  its  transform- 
ation, when  the  movements  become  obvious.  The 
same  mechanism  occurs  in  the  pupae  of  some  of  the 
fibrous  gall  flies  (Tephrites),  for  the  purpose  of  dis- 
severing the  woody  fibres  which  imprison  the  insects. 
In  the  instance  of  the  thistle  gall  fly  (  Tephriiis  Cardui), 
Reaumur  found  that  those  kept  in  his  study  often  be- 
came too  rigid  for  the  insects  to  force  their  passage, 
and  after  making  repeated  efforts  they  gave  up  the 
task  in  despair  and  died.*  In  the  open  air  this,  acci- 
dent is  prevented  by  the  rain  moistening  the  galls.  We 
have  more  than  once  had  occasion  to  make  the  same 
remark  in  the  woody  galls,  such  as  the  bedeguar  of 
the  rose,  in  which  the  flies  have  to  gnaw  for  them- 
selves a  passage,  but  which  they  cannot  always  effect 
when  the  galls  are  kept  through  the  winter  in  a  dry 
room.*)* 

In  another  genus  of  flies,  the  pupa  does  not  make 
use  of  its  head,  but  turns  round  and  employs  its  tail  to 
force  a  passage.  This  may  be  observed  in  the  pupa 
formed  from  the  rat-tailed  maggot  of  the  common- 
sewer  fly  (Eristalis  tenax,  FABRICIUS),  which  was  ob- 
served by  Reaumur  to  push  off  the  lid  of  its  pupa  case 
by  means  of  its  tail. 

The  caterpillar  of  the  clear-wing  hawk  moth 
(JEgcria  asiliformis,  STEPHENS),  before  going  into 
pupa,  gnaws  away  the  wood  of  the  poplar  tree, 
where  it  is  lodged,  till  it  leaves  only  a  plate  of  it  as 

*  Reaumur,  iv,  Mem.  8.  t  J.  K. 


MODES    OF    EMERGING    FROM    PUP-K.  323 

thin  as  writing-paper.  The  head  of  this  pupa  being 
obtuse ,  it  cannot  of  course  cut  through  this  wooden 
covering,  thin  as  it  is,  hut  can  only  push  against  it  till 
it  burst  it  open,  which  we  have  more  than  once  seen  it 
actually  do.*  It  is  enabled  to  exert  considerable  force 
in  this  process,  by  means  of  the  beautifully  serrated 
structure  of  its  rings,  resembling  in  this  respect  the 
caterpillars  of  cossus  and  other  wood-borers. 


pupse  of  Cossus,  a,  and  -<2Jg-m«,  6,  showing  the  serratures  of  their 
rings. 

Lyonnet  justly  remarks  that  in  the  cossus  there  are 
sharp  points  upon  the  head  for  the  purpose  of  making 
the  first  breach,  the  rest  of  the  body  acting  as  a  wedge 
to  tear  open  the  cocoon.  Professor  Peck  has  given  a 
very  interesting  account  of  similar  proceedings  in  the 
case  of  the  locust  moth  (  Cossus  Robinice,  PECK).  *  In 
the  silk  moth,'  he  says,  *  and  all  others  which  I  have 
had  an  opportunity  to  observe,  the  chrysalis  bursts  in 
the  cocoon,  and  the  fluid  which  surrounded  the  new 
insect  in  it  escaping  at  the  same  time,  so  weakens  or 
dissolves  the  fibre  and  texture  of  the  silk,!  that  the  moth 
is  able  to  extricate  itself,  leaving  the  chrysalis  behind  it; 
but  this  is  not  the  manner  in  the  locust  moth.  After  re- 
maining till  all  its  parts  are  fully  grown,  and  it  is  ready 
to  quit  its  prison,  a  certain  quantity  of  exercise  is  ne- 
cessary to.  break  the  ligaments  which  attach  the  moth 

+  J.  R. 

t  See  some  observations  on  this  doctrine,  *  Insect  Architec- 
ture,' pages  316,  317,  and  195. 


324  INSECT    TRANSFORMATIONS. 

to  the  shell  of  the  chrysalis,  and  to  loosen  the  folds  of 
the  abdomen.  In  taking  this  exercise,  it  can  only 
move  the  abdomen  in  various  directions;  as  one  side 
of  the  rings  is  moved  forward,  the  hooks  in  the  serrated 
lines  take  hold  of  the  silk  and  prevent  their  sliding 
back;  the  next  flexure  brings  forward  the  opposite  side 
of  the  rings,  which  are  prevented  by  the  points  on  that 
side  from  slipping  back  in  the  same  manner,  and  the 
chrysalis  is  forced  out  of  the  slightly- woven  extremity 
of  the  cocoon,  and  through  the  silk- lined  cavity,  till  it 
is  protruded  for  about  one-third  of  its  length  out  of  the 
opening  in  the  bark  and  into  the  air.'* 

A  no  less  ingenious  contrivance  for  escape  was  ob- 
served by  Bonnet  in  one  of  the  leaf-rollers,  which  feeds 
on  the  leaves  of  young  ash  trees.  It  rolls  up  the  leaf 
into  a  cone,  and  is  transformed  into  a  small  pupa,  re- 
sembling a  grain  of  oats.  The  chamber  which  it  forms 
is  not  only  extensive  in  proportion  to  the  size  of  the  in- 
sect, but  is  so  very  compact,  that  it  does  not  appear  in 
what  manner  it  is  to  effect  its  escape.  Within  the  ca- 
pacious chamber  of  t^he  leaf  it  hangs  itself  up  by  two 
lines,  after  the  manner  of  a  sailor's  hammock.  But, 
previous  to  this,  it  gnaws  a  circular  piece  half  through 
the  leaf,  taking  care  not  to  injure  the  exterior  mem- 
brane. In  order  to  render  this  little  door  easy  to  be 
found,  the  caterpillar,  as  if  foreseeing  that  the  blind 
pupa  could  not  otherwise  discover  it,  fixes  one  of  the 
suspensory  threads  near  its  margin,  guided  by  which 
the  insect  makes  its  exit  with  the  utmost  ease,  for  the 
head  is  uniformly  swung  up  by  the  door  thread. "f 

A  very  similar  proceeding  is  recorded  of  the  mi- 
nute granary  moth  (Tinea  granelia),  which  we 
have  before  mentioned  as  destructive  to  grain.  The 

*  Peck,  quoted  by  Kirhy  and  Spence. 
t  Bonnet.  QEuvres,  vol.  ii,  p.  207. 


MODES    OF    EMERGING    FROM   PUP^E.  325 

eggs  being  laid  on  the  outside  of  the  grain,  the 
entrance  of  the  caterpillar  into  the  interior  is  not 
larger  than  a  pin's  point,  and  of  course  entirely  use- 
less as  a  passage  for  the  moth  ;  but,  before  its  trans- 
formation into  the  pupa,  it  shapes  out  a  door  in  the 
skin  of  the  grain,  so  that  it  may  be  easily  broken  open 
from  within,  while  it  appears  entire  on  the  outside. 
By  pushing  it  accordingly  it  at  once  gives  way. 

A  prospective  contrivance  of  the  same  kind  occurs 
in  the  economy  of  a  caterpillar  which  lives  on  the 
dry  pith  in  the  seed  heads  of  the  wild  teazle  (Dipsa- 
cus  sylvestris).  The  hole  by  which  the  newly  hatched 
caterpillar  enters  is  so  minute,  that  in  some  hun- 
dreds of  teazle  heads,  containing  full-grown  ones, 
we  have  never  been  able  to  detect  it;  but  its  subse- 
quent proceedings  are  easily  traced.  From  the  first 
it  is  not  contented  with  the  protection  afforded  by 
the  walls  of  the  seed  head,  but  always  spins  a  gallery 
of  thick  silk  to  cover  it  while. feeding,  the  outside  of 
which  is  generally  covered  with  its  ejectamenta.  Up 
to  the  period  of  its  approaching  change,  the  walls  of 
the  seed  head  are  left  quite  enjtire,  as  it  only  eats  the 
dry  pith  contained  in  their  cavity;  but  through  these 
it  would  be  impossible  for  the  moth  to  make  its  way, 
inasmuch  as  it  is  unprovided  with  mandibles  for 
gnawing.  The  provident  caterpillar,  therefore,  takes 
care  before  its  change  to  cut  a  circular  hole  into  the 
teazle  at  the  end  of  its  own  silken  gallery,  through 
which  the  nascent  moth  may  find  an  easy  passage. 
Bonnet  gives  it  farther  credit  for  a  piece  of  ingenuity 
which  we  have  not  been  able  to  verify.  After  cutting 
the  hole,  he  tells  us,  it  carefully  fortifies  it  on  the  out- 
side by  amassing  the  fibres  and  seeds  of  the  plant  in 
a  loose  manner  over  the  hole,  to  prevent  the  intrusion 
of  rs-pacious  insects  from  without ;  and  he  gives  a 
very  minute  detail  of  his  discovery  of  this  fortifies^ 

VOL.  vi.  28 


326  INSECT    TRANSFORMATIONS. 

tion.*  But  we  have  only  to  examine  the  arrange- 
ment of  the  teazle  seeds  to  perceive  that  he  must 
have  been  mistaken.  In  a  dozen  specimens  now 
before  us  we  find  that,  besides  knawing  through  the 
wall,  the  insect  has  eaten  about  an  eigth  of  an  inch 
into  the  seeds  themselves  and  the  chaff  which  sur- 
rounds them,  leaving  on  the  outside  the  extremities 
untouched,  but  lining  the  whole  with  a  slight  tissue 
of  silk,  —  the  circumstance,  no  doubt,  which  misled 
Bonnet.  As  these  are  extremely  common  in  the 
vicinity  of  London,  almost  two-thirds  of  the  seed 
heads  of  teazle  containing  a  caterpillar,  the  pro- 
ceedings of  the  insect  may  be  easily  examined.! 

A  similar  prospective  contrivance  occurs  in  the  in- 
stance of  a  caterpillar  which  feeds  on  the  cow  parsnip 
(Heracleum  spondylium),  and  makes  a  circular  hole 
in  the  stem  for  the  exit  of  the  moth. 

In  all  the  preceding  instances,  the  pupa  is  left  to 
effect  its  extrication  by  its  own  unassisted  efforts. 
But  amidst  the  variety  which  claims  our  admiration 
in  the  economy  of  insects,  we  have  to  notice  pro- 
ceedings no  less  remarkable  in  the  case  of  those 
pupae  which  require  extraneous  assistance  in  their 
transformations.  An  instance  of  this  is  mentioned 
by  Kirby  and  Spence,  on  the  authority  of  the  Hon. 
Captain  Percy,  R.  N.,  who,  while  he  was  watching 
some  female  crane  flies  (Tipulce  oleracewl)  busily 
employed  in  depositing  their  eggs  amongst  the  roots 
of  grass,  saw  one  quitting  her  pupa  case.  She  had 
already,  by  her  own  efforts,  got  her  head,  shoulders, 
and  fore-legs  disengaged,  when  two  male  flies  arrived 
to  assist  in  her  extrication.  They  immediately  laid 
hold  of  her  pupa  case  with  their  anal  forceps  and  hind- 
legs,  while  with  their  fore-legs  and  mouths  they 
seemed  to  push  her  upwards,  moving  her  backwards 

*  Bonnet,  CEuvres,  vol.  ii,  obs.  xix.         t  J.  R. 


MODES    OF    EMERGING    FROM    PUP^E.  327 

and  forwards,  and  shifting  their  hold  till  she  was 
entirely  extr  cated,  when  they  left  her  to  recover  her 
strength  by  herself.  (  Probably,'  say  our  authors, 
*  the  extreme  length  of  the  two  pair  of  hind-legs  of, 
these  animals  may  render  such  assistance  necessary 
for  their  extrication.5^  We,  however,  imagine  that 
Captain  Percy's  instance  was  accidental  and  anoma- 
lous; for  the  insect  having  already  extricated  her  head, 
shoulders,  and  fore  -legs,  all  the  difficulties  were  sur- 
mounted. From  the  insect  being  so  very  common,  * 
also,  the  circumstance  of  such  assistance,  if  it  did 
happen,  must  be  matter  of  frequent  observation;  but 
we  have  witnessed  a  considerable  number  of  several 
species  of  this  family  undergo  the  change  without  any 
assistance  whatever.! 

The  best  ascertained  case  of  assistance  occurs 
among  ants,  and  was  first  observed  by  the  accurate 
Swedish  naturalist  De  Geer,  though  the  best  ac- 
count of  it  is  given  by  the  younger  Huber,  (  The 
greater  part  of  the  pupa?,'  says  he,  '  are  inclosed  in 
a  tissue  spun  by  themselves  before  their  change; 
but  they  cannot,  like  other  insects,  liberate  themselves 
from  this  covering  by  effecting  an  opening  in  it  with 
their  teeth.  They  have  scarcely  the  power  of  mov- 
ing; their  covering  is  of  too  compact  a  texture,  and 
formed  of  too  strong  a  silk,  to  allow  of  their  tearing 
it  without  the  assistance  of  the  workers.  But  how  do 
these  indefatigable  attendants  ascertain  the  proper 
moment  for  this  process?  If  they  possessed  the  fa- 
culty of  hearing,  we  might  imagine  they  knew  the  fit 
time,  from  some  noise  produced  in  the  interior  of  the 
prison  by  the  insects  whose  development  has  com- 
menced; but  there  is  no  indication  favouring  this 
opinion;  it  is  probable  they  have  a  knowledge  of  it 
from  some  slight  movements  that  take  place  within, 
which  they  ascertain  through  the  medium  of  their 

*  Intr.  iii,  286.  t  J.  R. 


328  INSECT   TRANSFORMATIONS. 

antennas ;  for  these  organs  are  endowed  with  a  sensi- 
bility, of  which  it  would  be  difficult  to  form  a  just 
idea:  whatever  it  be,  they  are  never  deceived. 

'  Let  us  still  follow  them  in  that  labour  in  which 
are  displayed  a  zeal  and  attachment  that  would  justly 
merit  our  attention,  even  were  they  the  real  parents 
of  these  pupae;  how  much  greater  then  must  be  our 
astonishment,  when  we  consider  that  they  bear  no 
further  relation  to  them  than  that  of  being  born  under 
the  same  roof.  Several  males  and  females  lay  in 
their  envelopes  in  one  of  the  largest  cavities  of  my 
glazed  ant-hill.  The  labourer-ants  assembled  toge- 
ther and  appeared  to  be  in  continual  motion  around 
them.  I  noticed  three  or  four  mounted  upon  one  of 
these  cocoons,  endeavouring  to  open  it  with  their 
teeth  at  that  extremity  answering  to  the  head  of  the 
pupa.  They  began  to  thin  it  by  tearing  away  some 
threads  of  silk  where  they  wished  to  pierce  it,  and  at 
length,  by  dint  of  pinching  and  biting  this  tissue,  so 
extremely  difficult  to  break,  they  formed  in  it  a  vast 
number  of  apertures.  They  afterwards  attempted  to 
enlarge  these  openings,  by  tearing  or  drawing  away 
the  silk;  but  these  efforts  proving  ineffectual,  they 
passed  one  of  their  mandibles  into  the  cocoon  through 
the  apertures  they  had  formed,  and  by  cutting  each 
thread,  one  after  the  other  with  great  patience,  at 
length  effected  a  passage,  of  a  line  in  diameter,  in  the 
superior  part  of  the  web.  They  now  uncovered  the 
head  and  feet  of  the  prisoner,  to  which  they  were  de- 
sirous of  giving  liberty,  but,  before  they  could  effect 
its  release,  it  was  absolutely  necessary  to  enlarge  the 
opening.  For  this  purpose  these  guardians  cut  out 
a  portion  in  the  longitudinal  direction  of  the  cocoon, 
with  their  teeth  alone,  employing  these  instruments 
as  we  are  in  the  habit  of  employing  a  pair  of  scissors. 
A  considerable  degree  of  agitation  prevailed  in  this 
part  of  the  ant-hill.  A  number  of  labourer-ants  were 


MODES    OF    EMERGING    FROM    PUPJE.  329 

occupied  in  disengaging  the  winged  individual  from 
its  envelope  ;  they  took  repose  and  relieved  each 
other  by  turns,  evincing  great  eagerness  in  seconding 
their  companions  in  the  task.  To  expedite  the  work, 
some  raised  up  a  little  slip  cut  out  in  the  length  of 
the  cocoon,  whilst  others  drew  the  insect  gently  from 
its  imprisonment.  When  the  ant  was  extricated  from 
its  enveloping  membrane,  it  was  not,  like  other  in- 
sects, capable  of  enjoying  its  freedom  and  taking 
flight ;  it  could  neither  fly,  nor  walk,  nor,  without 
difficulty,  stand  ;  for  the  body  was  still  confined  by 
another  membrane,  from  which  it  could  not  by  its 
own  exertions  disengage  itself. 

'  In  this  fresh  embarrassment,  the  labourer-ants 
did  not  forsake  it :  they  removed  the  satin-like  pel- 
licle which  embraced  every  part  of  the  body,  drew 
the  antennae  gently  from  their  investment,  then  dis- 
engaged the  feet  and  the  wings,  and  lastly  the  body, 
with  the  abdomen  and  its  peduncle.  The  insect  was 
now  in  a  condition  to  walk  and  receive  nourishment , 
for  which  it  appeared  there  was  urgent  need.  Tta 
first  attention,  therefore,  paid  it  by  the  guardians  was 
that  of  giving  it  the  food  I  had  placed  within  their 
reach. 

*  The  ants  in  every  part  of  the  ant-hill  were  occu- 
pied in  giving  liberty  to  the  males,  females,  and 
young  labourer-ants,  which  were  still  enveloped.  On 
being  disencumbered  of  their  coverings,  the  rem- 
nants were  collected  and  placed  aside  in  one  of  the 
most  distant  lodges  of  their  habitation;  for  these  in- 
sects observe  the  greatest  order  and  regularity. 
Some  species  of  ants  remove  these  shreds  to  a  dis- 
tance from  the  ant-hill,  others  cover  the  exterior  sur- 
face of  their  nest  with  them,  or  collect  them  in  partic- 
ular apartments.'* 

A.  very  interesting  experiment  upon  this  subject 
was  tried  by  Dr  J.  R.  Johnson,  of  Bristol.  '  Among 

*  Huber  on  Ants,  p.  88. 
VOL.  vi.  28* 


330  INSECT    TRANSFORMATIONS, 

those  ants  I  kept  in  confinement,'  says  he,  e  I  ob- 
served that  considerable  bustle  prevailed  when  any  of 
the  pupae  were  about  to  quit  the  cocoon.  For  the 
most  part  two  or  three  stationed  themselves  on 
or  near  each  cocoon.  From  seeing,  more  than 
once,  two  engaged  in  the  operation,  I  placed 
in  a  wine-glass,  with  a  little  moistened  earth, 
one  of  the  yellow  ants  (Formica  flava),  with 
three  or  four  pupa?;  the  first  object  with  this  little 
creature  was  that  of  excavating  a  chamber  for  the 
deposition  of  its  treasure.  The  pupae  were  then 
brought  up,  and  laid  on  the  surface  of  the  earth  from 
day  to  day,  to  receive  the  sun's  warmth.  In  a  few 
days  I  saw  the  scattered  remnants  of  one  of  the 
cocoons,  and  the  worker,  with  his  assistant,  engaged 
in  giving  liberty  to  the  remaining  ants.  I  did  not, 
at  the  time,  notice  whether  the  pupae  were  or  were 
not  capable  of  effecting  their  own  liberation;  but  ac- 
cording to  the  statement  of  De  Geer,  the  pupae  dies 
when  neglected  by  the  workers.'* 

The  latter  circumstance  is  contradicted  by  the 
testimony  of  Swammerdam,  one  of  the  highest 
authorities  which  could  be  adduced.  The  species  he 
describes  as  flesh-coloured,  and  he  was  not  a  little 
surprised  that  they  spun  a  cocoon  like  the  silk-worm. 
1  This  web,'  he  says,  '  was  of  an  oval  figure,  and 
wrought  with  delicate  and  fine  threads  about  the 
body,  being  of  a  rusty  iron  colour,  and  when  I  opened 
it  I  found  a  pupa  in  the  interior.  I  likewise  carried 
some  of  these  enclosed  pupa?  to  Amsterdam,  which 
after  some  days  gnawed  their  way  out  of  their  webs, 
and  produced  some  male  ants:  this  happened  on  the 
eighteenth  of  July.'f  It  is  obvious,  therefore,  that 
at  least  some  species  can  extricate  themselves  with- 
out assistance;  though  this  seems  to  be  the  regular 
process. 

*  Notes  to  Huber,  p.  87. 

t  Swammerdam,  Biblia  Nat.,  vol.  i,  p.  ISO, 


MODES   OF    EMERGING   FROM    PUP.E.  33* 

We  might  have  been  led  by  analogy  to  suppose 
that  bees  would  adopt  a  similar  method  of  extricating 
their  young;  but  observation  shows  that  they  do 
not,  for  they  break  through  their  cocoon  by  means  of 
their  mandibles,  at  the  same  time  forcing  their  way 
through  the  wax  that  is  fastened  down  above  to  the 
web  and  bursting  it  into  several  jagged  pieces,  which 
they  throw  off  on  all  sides.  The  other  bees  carry 
these  broken  pieces  away,  and  clear  the  cells  so  thor- 
oughly as  to  make  them  quite  smooth  and  even. 
The  male,  as  well  as  the  queen  bees,  force  their  way 
also  out  of  their  cells  in  the  same  manner  as  the 
common  or  working  .kind,  and  all  undergo  the  same 
change.*  But  there  is  one  very  remarkable  difference 
peculiar  to  the  royal  cocoons,  first  observed  by  the 
elder  Huber,  which  well  merits  to  be  mentioned. 

A  hive  of  bees  is  so  essentially  monarchical,  that 
when  more  queens  than  one  are  produced  they  ex- 
hibit mutual  and  deadly  animosity,  which  leads  them 
to  destroy  one  another.  When  there  are  several 
royal  pupse,  therefore,  in  a  hive,  the  first  transformed 
attacks  the  rest  and  stings  them  to  death;  though,  if 
these  pupaB  were  enveloped  in  complete  cocoons,  this' 
murder  could  not  be  perpetrated;  —  for  the  silk  is  of 
so  close  a  texture,  that  the  sting  could  not  penetrate 
it;  and  if  it  did,  the  barbs  would  stick  fast  in  the 
meshes,  and  the  royal  assailant,  unable  to  retract  her 
weapon,  would  become  the  victim  of  her  own  fury. 
In  order,  therefore,  that  she  may  destroy  her  rivals, 
it  is  necessary  for  the  hinder  rings  to  remain  unco- 
vered, and  on  this  account  it  is  inferred  the  royal 
grubs  spin  only  imperfect  cocoons,  open  behind,  and 
enveloping  only  the  head,  shoulders,  and  first  ring  of 
the  abdomen. 

Huber  was  exceedingly  anxious  to  discover  whe- 
ther the  royal  grubs  spun  their  cocoons  imperfect  in 
consequence  of  a  particular  instinct,  or  of  the  greater 

*Swammerdam,  vol.  i,  p.  187. 


332  INSECT    TRANSFORMATIONS. 

width  of  the  cells  preventing  them  from  stretching 
the  thread  up  to  the  top.  To  ascertain  this  he  dis- 
lodged several  royal  grubs  about  to  spin  their 
cocoons,  and  introduced  them  into  glass  cells  blown 
of  varying  dimensions.  '  They  soon  prepared  to 
work,'  he  says,  c  and  commenced  by  stretching  the 
fore  part  of  the  body  in  a  straight  line,  while  the 
other  was  bent  in  a  curve,  —  thus  forming  an  arc  of 
which  the  sides  of  the  cells  afforded  two  points  of 
support.  It  next  directed  the  head  to  such  parts  of 
the  cell  as  it  could  reach,  and  carpeted  the  surface 
with  a  thick  bed  of  silk.  I  remarked  that  the  threads 
were  not  carried  from  one  side  to  another,  which 
would  have  been  impracticable,  for  the  larvae,  being 
obliged  to  support  themselves,  had  to  keep  the  pos- 
terior rings  curved;  and  the  free  and  moveable  part 
of  the  body  was  not  long  enough  to  admit  of  the 
mouth  reaching  the  opposite  sides.  The  first  expe- 
riments obviated  the  probability  of  any  particular  in- 
stinct in  the  royal  larvae,  and  proved  that  they  spin 
incomplete  cocoons,  because  they  are  forced  to  do  so 
by  the  figure  of  their  cells.  But  desirous  of  evidence 
still  more  direct,  I  put  them  into  cylindrical  glass 
cells,  where  I  had  the  satisfaction  of  seeing  them 
spin  complete  cocoons  in  the  same  manner  as  the 
larvae  of  workers.  In  fine,  I  put  plebeian  larvae  into 
very  wide  cells,  and  they  left  the  cocoon  open,  as  is 
done  by  the  royal  larvcP.  I  also  found  that  royal 
larvae,  when  lodged  in  artificial  cells,  where  they  can 
spin  complete  cocoons,  undergo  all  their  transforma- 
tions equally  well.  Thus  the  necessity  which  nature 
imposes  on  them  of  leaving  the  cocoon  open,  is  not 
on  account  of  their  increment;  nor  does  it  appear  to 
have  any  other  object  than  that  of  exposing  them  to 
the  certainty  of  perishing  by  the  wounds  of  their 
natural  enemy ;  —  an  observation  truly  new  and  siq-* 
gular.'* 

*  Huber  on  Bees,  p.  133, 


SECT.  IV.  — PERFECT  INSECTS. 


CHAPTER  XIV. 

Expansion  of  the  Body  and  Wings  in  Insects  newly  transformed'. 

THE  mechanism  by  which  winged  insects,  as  well  as> 
birds,  are  enabled  to  support  themselves  in  the  air,  is 
one  of  the  most  admirable  instances  of  providential 
wisdom,  to  facilitate  the  locomotion  and  the  distribu- 
tion of  the  smaller  animals.  The  great  agent  em- 
ployed for  this  purpose  is  air,  which  is  made  to 
serve  the  double  purpose  of  assisting  in  the  assimi- 
lation of  nutriment  by  the  supply  of  oxygen  and  the 
removal  of  carbon,  and  of  diminishing  the  weight  of 
the  body  in  order  to  render  it  buoyant  In  birds, 
the  lungs  have  several  openings  communicating  with 
corresponding  air-bags  or  cells  which  fill  the  whole 
cavity  of  the  body  from  the  neck  downwards,  and 
into  which  the  air  passes  and  repasses  in  the  pro- 
cess of  breathing.  This  is  not  all:  the  very  bones  of 
birds  are  hollowed  out  with  the  design  of  receiving 
air  from  the  lungs,  from  which  air-pipes  are  con- 
veyed to  the  most  solid  parts  of  the  body,  and  even 
into  the  quills  and  plumelets  of  the  feathers,  which  are 
hollow  or  spongy  for  its  reception.  As  all  these 
hollow  parts,  as  well  as  the  cells,  are  only  open  on 
the  side  communicating  with  the  lungs,  the  bird 
requires  only  to  take  in  a  full  breath  to  fill  and  dis- 
tend its  whole  body  with  air,  which,  in  consequence 
of  the  considerable  heat  of  its  body,  is  rendered  much 
lighter  than  the  air  of  the  atmosphere.  By  forcing 
this  air  out  of  the  body  again,  the  weight  becomes  so 


334  INSECT    TRANSFORMATIONS. 

much  increased  that  birds  of  large  size  can  dart  down 
from  great  heights  in  the  air  with  astonishing  velocity. 

In  insects  a  similar  mechanism  occurs,  though  it 
is  more  difficult  to  trace  it,  on  account  of  the  great 
minuteness  of  the  several  organs;  but  so  far  as  the 
circumstances  can  be  observed,  they  well  merit  our 
attention.  The  most  remarkable  of  these  is  the 
expansion  of  the  body  and  wings  on  the  perfect 
insect  emerging  from  the  pupa  case.  A  very 
striking  exemplification  of  this  occurs  in  the  trans- 
formation of  the  ant-lion  (Myrmeleon  formicarium,) 
whose  singular  stratagems  in  the  grub  state  are  so 
familiar  to  the  readers  of  books  on  natural  history.* 
When  it  is  about  to  change  into  a  pupa  it  constructs 
a  cocoon  of  sand,  which  it  lines  with  a  beautiful 
tapestry  of  silk,  the  whole  being  less  than  half  an 
inch  in  diameter,  the  pupa  itself,  when  rolled  up, 
filling  only  a  space  of  about  half  this  dimension. 
When  it  has  remained  in  the  cocoon  about  three 
weeks,  it  breaks  through  the  envelope  and  emerges  to 
the  outside,  as  the  chrysalides  of  wood-borers  make 
their  way  to  the  exterior  of  a  tree  to  facilitate  the  exit 
.of  the  perfect  insect;  with  this  difference,  that  the 
nascent  myrmeleon-fly  makes  use  of  its  mandibles  to 
gnaw  the  cocoon.  When  it  has  arrived  on  the  out- 
side it  only  requires  to  expand  its  wings  and  body  to 
complete  its  transformation.  But  this  is  the  process 
most  calculated  to  excite  our  admiration;  for  though 
it  is  not  on  its  emergence  more  than  half  an  inch  in 
length,  it  almost  instantaneously  stretches  out  to  an 
inch  and  a  quarter,  while  its  wings,  which  did  not 
exceed  the  sixth  of  an  inch,  acquire  an  immediate 
expansion  of  nearly  three  inches. 

To  the  real  wonders  attending  the  history  of  this 
remarkable  insect,  it  has  been  fancifully  added,  that, 
as  it  has  cast  off  the  spoils  and  cumbersome  weight 

*  See    s  Insect  Architecture,'    page  209,  &c. 


EXPANSION   OF   PERFECT   INSECTS. 


335 


of  its  first  form,  so  it  is  likewise  divested  of  its  barbar- 
ity and  ravenous  malignity;  but  the  formidable  struc- 
ture of  its  mandibles,  as  Reaumur  justly  remarks,  evi- 
dently disprove  this  opinion.  A  lady  discovered  that 
it  would  eat  fruit,  and  Reaumur  actually  saw  one 
munch  part  of  a  pear;  but  he  thinks  that  this  is  not  its 
natural  food.*  Its  close  resemblance,  indeed,  to  the 
dragon-flies  (Libellulina,)  except  in  being  more  slow 
in  flight,  affords  a  strong  analogical  indication  of  its 
carnivorous  propensities. 


c,  Afyrmelton  formicarium,  the  fly  of  the  ant-lion,  fe,  the  head 
magnified  to  show  the  calliper-formed  mandibles,  c,  the  pupa, 
rf,  the  pupa  escaping  from  its  cocoon. 


A  still  more  striking  difference  of  size  tnay  be 
remarked  in  the  pupa  and  the  perfect  insect  of  a  lace- 
winged  fly  (Chrysopa  Perla,  LEACH,)  by  no  means 
uncommon  near  London,  and  well  known  by  its 
golden  eyes  and  green  wings.  |  The  cocoon  of  this 


Mem,  vol.  vi,  p.  375, 


t  Seepage  45, 


336  INSECT    TRANSFORMATIONS. 

insect  is  not  bigger  than  a  small  pea,  while  the  fly  is 
nearly  an  inch  in  length,  and  the  expanse  of  the  wings 
about  two  inches. 

In  some  aquatic  insects  this  transformation  is  the 
more  conspicuous  from  the  change  of  element,  the 
pupa  emerging  into  the  dry  atmosphere,  where  the  fly 
is  evolved.  In  the  case  of  the  dragon-flies  just  men- 
tioned, the  approaching ,  change  is  evinced  by  the 
increasing  transparency  of  the  pupa,  exhibiting  the 
growing  brilliancy  of  the  large  lustrous  eyes  of  the  in- 
cluded insect,  which  may  be  then  brought  into  view 
by  removing  the  envelope.  At  this  period  it  may  be 
seen  removing  out  of  the  water  to  a  dry  place,  such 
as  a  grassy  bank  or  the  stems  of  aquatic  plants,  into 
which  it  pushes  its  sharp  claws,  and  remains  for  a 
short  time  immovable.  By  the  swelling  of  the 
upper  part  of  the  body  the  envelope  is  soon  distended 
and  burst  asunder  on  the  back  of  the  head  and 
shoulders,  and,  through  the  opening,  first  the  head 
and  then  the  legs  of  the  perfect  fly  make  their  exit, 
whilst  the  empty  slough  of  the  legs  continues  fixed 
in  its  place.  After  this  first  part  of  the  process  is 
accomplished,  it  hangs  down  its  head  and  rests  for 
a  space,  as  if  exhausted  by  previous  exertion,  or 
rather  to  allow  the  newly  excluded  parts  to  dry  and 
become  mote  firm.  It  next  erects  itself,  and  laying 
hold  of  the  upper  part  of  the  slough  with  its  feet, 
pulls  the  parts  still  enveloped  further  out,  then 
creeping  forward  by  degrees,  it  disengages  the  en- 
tire body,  and  again  rests  for  a  time  immovable. 
The  wings  now  begin  to  expand  themselves,  and 
their  plaits  and  folds  become  gradually  smooth. 
The  body,  also,  becomes  insensibly  larger  and 
longer,  and  the  limbs  acquire  their  just  size  and  pro- 
portions. While  the  wings  are  undergoing  this 
operation  of  drying  and  expanding,  the  insect  takes 
care  to  keep  them  from  coming  into  contact  with  tho 


EXPANSION    OF    PERFECT    INSECTS. 


337 


A,  the  dragon-fly,  beginning  to  escape  from  the  pupa;  a,  the  fly;  6,the 
pupa  case.  B,  The  process  further  advanced;  c,  the  fly;  d,  the  pupa 
case.  C,  the  fly  nearly  free,  and  forming  an  arch;  e,  the  fly;/,  the 
pupa  case.  D,  the  fly  bending  back  its  body,  so  as  not  to  obstruct  the 
expansion  of  the  wings. 

VOL.  vi.  29 


338  INSECT    TRANSFORMATIONS. 

body,  by  bending  itself  into  the  form  of  a  crescent; 
for  if  they  were  obstructed,  whilst  wet,  they  could  not 
afterwards  be  set  to  rights. 

All  these  changes  are  perfected,  according  to  Swam- 
merdam,  by  the  force  of  the  circulating  fluids  and  the 
air,  impelled  by  respiration,  a  fact  of  which,  we  think, 
there  cannot  be  any  doubt.  It  is  very  seldom,  how- 
ever, that  we  can  surprise  insects  at  the  precise  mo- 
ment of  their  transformation,  as  it  is  for  the  most  part 
very  speedily  accomplished,  for  the  whole  of  the  pre- 
ceding evolutions  are  usually  completed  in  ten  or  fif- 
teen minutes.  '  It  happened  by  mere  chance,'  says 
Swammerdam,  'that  I  observed  them  for  the  first  time: 
one  of  these  vermicles  adhered  to  a  stone-wall  in  the 
river  Loire,  and  it  was  so  softened  by  the  water  dash- 
ing up  against  it,  that  it  could  only  half  perfect  its 
change,  so  that  I  took  it  partly  free  and  partly  yet 
fixed  in  the  skin.  I  once  afterwards  saw  this  change 
in  the  large  kind  of  dragon-fly  (JEshna?)  which  had 
crept  to  land  out  of  a  small  lake,  and  cast  its  skin  sit- 
ting in  the  grass.'* 


c,  newly-hatched  blow-fly  magnified,  showing  the  pulpy, 
crumpled  state  of  the  wings.  6,  the  wings  dry  and  fully  ex- 
panded. 

*  Bibl.  Nat.,  vol.  i,  p.  98. 


EXPANSION    OF    PERFECT    INSECTS.  339 

Some  species  of  flies  have  their  wings  shortened 
very  considerably  in  the  pupa  state  by  zig-zag  or  trans- 
verse folds;  so  that,  when  newly  evolved,  it  might  be 
supposed,  from  their  moist  and  crumpled  appearance, 
that  they  could  never  become  so  fine,  gauzy,  and  trans- 
lucent, as  they  are  actually  seen  to  do.  This  will  be 
better  understood  from  the  above  figures  than  by  de- 
scription. 

We  have  taken  the  preceding  examples  of  expan- 
sion of  the  wings  from  those  insects  in  which  these  are 
more  or  less  transparent,  and  consequently  the  branch- 
ing of  the  tubes  (nervures)  through  them  is  more  obvi- 
ous than  in  moths  and  butterflies,  in  which  the  wings 
are  covered  with  feathery  scales.  It  is,  however,  less 
rare  to  see  the  latter  transformed  than  the  former, 
from  the  greater  facility  of  rearing  them,  and  on  that 
account,  it  may  be  proper  to  take  some  notice  here 
of  their  transformation.  We  cannot  in  this  find  bet- 
ter guides  than  Swammerdam  and  the  celebrated  Italian 
anatomist,  Malpighi,  in  his  account  of  the  silk-worm. 
'At  length,'  says  the  latter,  '  within  four  days,  the  heart 
(dorsal  vessel)  of  the  silk-worm  continues  moving  slowly, 
and  the  body  growing  bigger;  having  thrown  off  the 
outward  skin  like  a  slough,  the  pupa  appears  a  new 
creature.  The  throwing  off  the  old  and  assuming  this 
new  form,  is  completed  in  the  space  of  one  minute  and 
ten  seconds;  and  it  is  thus  done,  as  I  chanced  to  see 
it.  The  motion  of  the  heart  (dorsal  vessel)  is  very 
quick  at  first,  and  the  whole- frame  of  the  body  appears 
convulsed;  so  that  the  several  circular  folds  of  the  seg- 
ments emerge,  and  by  the  transverse  contraction  of  the 
sides,  the  external  skin  is  separated  from  the  inner; 
hence,  upon  making  an  eflhrt,  and  thrusting  the  body, 
which  now  appears  particularly  thick  towards  the  head, 
the  skin  is  driven  backward  and  downward;  and  the 


340  INSECT    TRANSFORMATIONS. 

portions  of  the  windpipe  being  separated  from  their  ex- 
ternal proper  orifices,  are  thrown  away  with  the  skin 
which  is  then  cast  off.  By  this  motion,  a  cleft  or  open- 
ing is  made  in  the  back  near  the  head,  and  through  the 
aperture  the  body  makes  its  way,  the  skin  being  by  de- 
grees drawn  back  towards  the  tail.  This  process  is 
assisted  greatly  by  a  yellow  kind  of  ichor  which  exudes 
from  the  cavities  t>f  the  skull;  and  the  pupa  appears 
then  free  and  disengaged. 

'  While  the  insect  is  making  its  passage  out,  the 
antennae  are  separated  from  the  body  of  the  pupa, 
and  are  torn,  as  it  were,  out  of  two  cavities  of  the 
skull ;  and  their  length,  as  they  become  unfolded, 
occupies  the  same^place  which  the  two  muscles  of  the 
mandibles  ^o^^ty  occupied.  The  wings,  also,  and 
the  legs  appear  to  be  circumscribed  in  their  limits; 
the  wings  being  drawn  from  their  situation  near  the 
fore-legs,  and  the  legs  from  the  lateral  parts  of  the 
back.  But  as  these  unfolded  parts  are  yet  mucous, 
they  easily  stick  to  each  other,  and,  insensibly  grow- 
ing dry,  they  become  so  closely  united  that  the  pupa 
appears  like  one  entire  garment.  Now  as  these  parts 
are  peculiar  to  the  moths,  and  are  destined  for  their 
use,  the  nature  of  the  moths  seems  to  be  to  emerge 
sooner  from  the  state  of  the  caterpillar  than  is  com- 
monly believed,  and  also  to  be  earlier  implanted 
in  it;  for  evidently,  in  the  silk-worm,  the  beginnings 
of  the  wings  may  be  seen  under  the  second  and 
third  ring  of  the  body,  .before  the  texture  of  the 
web.  The  antennas  are  likewise  delineated  on  the 
skull,  and  the  web  being  finished,  they  have  their 
own  termination;  nor  will  it  be  improper  to  suppose 
that  the  new  kind  of  life  in  the  pupa  is  only  a  mask 
or  veil  of  the  moth,  which  is  already  perfect  within, 
the  intent  of  which  is,  that  it  should  not  be  struck  01 


EXPANSION    OF    PERFECT    INSECTS.  341 

destroyed  by  external  injuries,  but  migbt  grow  strong 
and  ripen.'* 

While  the  little  creature  remains  in  this  condition, 
there  is  produced,  as  Swammerdam  tells  us,  a  violent 
agitation  in  its  fluids,  so  that  they  are  driven  from  the 
internal  vessels  through  the  tubes  in  the  wings,  which 
are  likewise  supplied  with  air  from  the  windpipe.  The 
insect,  besides,  labours  violently  with  its  legs,  and  all 
these  motions  concurring  with  the  growth  of  the  wings, 
it  is  impossible  that  the  tender  skin  which  covers  it 
should  not  at  length  give  way,  which  it  does  by  burst- 
ing in  four  distinct  and  regular  pieces.  When  the  legs 
become  disengaged  they  much  assist  in  freeing  the  body 
and  other  parts  that  are  yet  bound  up;  at  the  same  time, 
the  skin  on  the  back  flies  open  and  uncovers  the  wings 
and  shoulders.  The  insect,  after  this,  remains  for 
some  time  in  a  state  of  rest,  with  its  wings  drooping 
down  like  wet  paper,  and  its  legs  fixed  in  the  skin 
which  it  has  just  cast  off,  together  with  the  lining  of 
the  windpipe  and  breathing  spiracles.  This  latter  cir- 
cumstance enables  the  insect  to  take  more  air  into  its 
body,  and  thereby  renders  it  the  better  able  to  fly,  and 
perform  the  other  functions  dependant  on  a  good  sup- 
ply of  air.  In  consequence  of  this  the  wings  expand 
so  rapidly,  that  it  is  by  no  means  easy  to  trace  their 
unfolding;  for  in  the  space  of  a  few  minutes,  they  in- 
crease in  dimensions  about  five-fold.  Their  spots  and 
colours  at  the  same  time,  previously  so  small  as  to 
be  scarcely  discernible,  become  proportionally  extend- 
ed, so  that  what  but  a  few  minutes  before  appeared  as 
a  number  of  confused  and  indistinct  points,  acquires 
many  varied  beauties  of  colour  and  form.  From  the 
wings  extending  themselves  so  suddenly,  their  soft 
wrinkled  appearance  is,  in  less  than  half  an  hour, 

*  Malpighi,  De  Bornbyce. 
VOL.  vi.  29* 


342  INSECT    TRANSFORMATIONS. 

no  longer  visible,  and  the  insect  becomes  fitted  tor 
flight.* 

Kirby,  in  speaking  of  the  swallow-tailed  butterfly 
(Papilio  Machaori),  says,  c  I  had  the  pleasure  of  see- 
ing it  leave  its  puparium  the  16th  of  May.  With  great 
care  I  placed  it  upon  my  arm,  where  it  kept  pacing 
about  for  the  space  of  more  than  an  hour;  when  all  its 
parts  appearing  consolidated  and  developed,  and  the 
animal  perfect  in  beauty,  I  vsecured  it,  though  not  with- 
out great  reluctance, for  my  cabinet  —  it  being  the  only 
living  specimen  of  this  fine  fly  I  had  ever  seen.  To 
observe  how  gradual,  and  yet  how  rapid,  was  the  de- 
velopment of  the  parts  and  organs,  and  particularly  of 
the  wings,  and  the  perfect  coming  forth  of  the  colour 
and  spots,  as  the  sun  gave  vigour  to  it,  was  a  most  in- 
teresting spectacle.  At  first,  it  was  unable  to  elevate 
or  even  move  its  wings;  but  in  proportion  as  the  aerial 
or  other  1  uid  was  forced  by  the  motions  of  its  trunk 
into  their  nervures,  their  numerous  corrugations  and 
folds  gradually  yielded  to  the  action  till  they  had  gain- 
ed their  greatest  extent,  and  the  film  between  all  the 
nervures  became  tense*  The  ocelli,  and  spots  and 
bars,  which  appeared  at  first  as  but  germs  or  rudiments 
of  what  they  were  to  be,  grew  with  the  growing  wing, 
and  shone  forth  upon  its  complete  expansion  in  full 
magnitude  and  beauty. 'f 

The  probable  object  of  the  movements  which  an 
insect  makes,  upon  just  escaping  from  the  chrysalis, 
is  to  impel  the  fluids  that  had  been  compressed 
during  its  confinement,  and  more  particularly  air, 
into  the  various  parts  of  the  expanding  body  and 
wings.  The  wings,  it  may  be  remarked,  are  not,  on 
the  exclusion  of  the  iiioect,  folded  up  as  are  the  long 
wings  of  an  earwig  (Forficula  auricularia) ,  but  are 

*  Swammerdam,  ii,  7,  &c.  t  Intr.  iii,  293. 


STRUCTURE     OF    WINGS.  343 

of  a  thick  structure  and  easily  expanded.  They  differ 
in  this  from  full-formed  wings,  which  cannot  be  stretch- 
ed a  hair's  breadth  without  tearing  them;  whereas  we 
have  taken  the  wing  of  a  butterfly  on  its  emerging 
from  the  chrysalis,  and  extended  it  to  four  times  its 
original  expansion.  That  the  fluids  of  the  body  are 
at  this  period  impelled  into  the  wings,  is  proved  by 
an  experiment  first  tried,  we  believe,  by  Swammer- 
dam,  on  the  wings  of  bees.  <  The  blood  in  the  bee,' 
he  says,  <  is  a  limpid  fluid,  as  may  be  observed,  if  a 
little  part  be  at  this  time  cut  off  from  the  wings;  for 
then  the  fluid  exudes  from  the  cut  part,  appearing,  by 
reason  of  the  extreme  smallness  of  the  blood-vessels, 
under  the  form  of  little  pellucid  globules,  which  in- 
sensibly and  fyy  degrees  increase  into  considerable 
little  drops.'  —  'The  wings  of  the  bee  have  likewise 
many  pulmonary  tubes,  which,  when  the  nymph  is 
casting  its  last  skin,  have  also,  together  with  all  the 
other  parts,  once  more  to  throw  off  their  exuviae. 
After  this,  when  these  tubes  are  again  distended  by 
the  freshly  impelled  air,  and  the  air-vessels,  which 
have  hitherto  been  contracted,  are  inflated  and  dis- 
tended with  the  same  air,  it  follows  that  the  whole 
wing  afterwards  expands  itself,  and  becomes  thrice, 
nay,  four  times  larger  than  it  was  before.  This  ex- 
pansion of  the  wings  depends,  therefore,  both  upon 
the  impulsion  of  the  air  and  of  the  blood;  for  at  the 
same  time  v;hen  the  air  is  impelled  into  the  wings,  a 
considerable  quantity  of  blood  is  likewise  driven  into 
the  vessels  of  the  wings.'  —  'The  female  bees  do  not, 
as  the  common  bees  and  the  male,  come  forth  with 
their  wings  folded  up,  but  expanded  and  displayed, 
and  in  a  state  ready  for  flight.  On  this  account,  the 
all-wise  Author  of  Nature  has  provided  for  them  a 
more  spacious  mansion,  in  which  they  may  expand 
their  wings  conveniently  and  properly;  so  that  after 
they  have  burst  from  their  cells  they  may  be  pre- 


344 


INSECT    TRANSFORMATIONS. 


pared  for  swarming  immediately,  if  there  be  a  necessity 
for  it,  or  that  the  young  queen  may  be  in  a  'condition 
to  drive  out  her  royal  mother  and  take  her  place  if  there 
be  occasion.'* 

It  does  not  appear,  however,  that  Swammerdam 
proved  by  dissection  the  simultaneous  existence  of 
air  and  blood  vessels  in  the  wings,  but  merely  infers 
this,  as  Reaumur  afterwards  did,  from  the  phenomena. 
But  Jurine  has  since  actually  demonstrated  that  every 
vein  (nervure}  of  a  wing  contains  an  air-tube,  which 
originates  in  the  windpipe,,  and  follows  in  a  serpentine 
form,  without  filling,  every  branchlet  of  the  nervures. 
Those  who  have  not  paid  attention  to  this  curious  sub- 
ject have  little  conception  of  the  great  diversity  of  forms 
which  are  exhibited  by  the  branchings  of  these  nervures, 
.  not  only  in  different  orders,  but  even  in  different  spe- 
cies of  insects.  They  differ,  indeed,  as  much  in  this 
respect  as  the  leaves  of  plants  do  in  their  mode  ot 
veining. 


Wings  of  insects :  —  or,  wing  of  a  beetle  ;  6,  wing  of  an  earwig; 
f,  wing  of  a  saw-fly  5  <7,  wing  of  a  crane-fly  ;  e,  wing  of  a  com 
nion  fly  (Musca)  ;  /,  wing  of  a  midge  (Psychoda). 

*  Swammerdam,  i,  187. 


STRUCTURE    OF    WINGS.  345 

In  moths  and  butterflies  the  nervures  are  in  a  great 
measure  concealed  by  the  feathery  scales;  —  but  when 
these  are  removed  they  are  rendered  apparent,  and 
appear  to  resemble  in  some  measure  the  arrangement 
observed  in  the  two-winged  flies.  To  this  arrange- 
ment there  occurs  a  remarkable  exception  in  the 
family  of  plumed  moths  (JHucitidce,  LEACH),  of 
which  Stephens  enumerates  twenty-nine  British 
species.  One  of  the  most  common  of  these  is  the 
large  white  plume  (Pterophorus  pentadactylus, 
LEACH),  which  may  be  seen,  during  the  summer,  in 
hedges  and  gardens,  flitting  about  like  a  tuft  of  down 
or  a  snow-white  feather  dropt  from  the  breast  of  the 
eider  duck.  From  being  slow  in  its  motions  it  is 
easily  taken;  but  if  rudely  handled  all  its  snowy 
plumage  will  come  off.  Another  of  the  family,  also 
very  common,  is  the  twenty-plume  moth  (Alucita 
hexadactyla,  LEACH),  which  may  be  seen  from  March 


a,  the  twenty-plume  moth.    6,  the  same  magnified,    c,  the  white 
plume  moth. 

till  October,  on  windows  and  the  walls  of  rooms,  or, 
still  more  probably,  on  the  leaves  of  honey-suckles, 


346  INSECT    TRANSFORMATIONS. 

on  which  its  caterpillar  feeds.  Reaumur,  who  had 
never  found  the  caterpillar,  thought  that  so  delicate 
an  insect  could  not  exist  out  of  doors  during  the  bleak 
weather  of  spring;  and  concludes  that  it  feeds  like 
the  clothes  moth  in-doors  —  an  instance  among  hun- 
dreds more  how  frequently  our  most  plausible  reason- 
ings are  far  removed  from  the  facts.  This  moth  is  so 
small  that  it  is  not  ready  to  catch  the  eye  of  those  who 
are  unacquainted  with  it,  and  even  when  it  is  found 
it  requires  a  magnify  ing- glass  to  perceive  all  its 
beauties. 

The  movements  of  insects  just  escaped  from  the 
chrysalis  appear,  then,  to  be  analogous  in  their  design 
to  the  restless  motions  of  the  young  of  larger  animals. 
In  Darwin's  fanciful  language,  the  accumulation  of 
excitability  in  the  sensorium  impels  the  creature  to 
be  frisky  for  the  purpose  of  getting  rid  of  the  super- 
abundant stimulus;  but  whatever  the  exciting  cause 
may  be,  we  are  certain  that  the  final  cause  and  certain 
effect  is  the  brisker  impulsion  of  fluids,  and  particu- 
larly air,  through  the  vessels  appropriated  to  their 
circulation,  and  consequently  the  more  perfect  nour- 
ishment and  speedy  growth  of  the  several  members. 
The  analogy  between  the  larger  animals  and  insects 
is,  that  the  latter,  when  they  have  undergone  their 
last  change  from  the  pupa  into  the  perfect  insect,  never 
increase  in  size,  as  the  former  remain  stationary  soon 
after  puberty. 

We  notice  this  the  more  readily,  as  those  who  are 
but  little  acquainted  with  insects  are  exceedingly 
apt  to  think  they  grow  like  other  animals,  and  from 
this  cause  commit  many  mistakes,  not  perhaps  of 
great  moment,  but  which  in  a  work  like  this  it  may 
prove  interesting  to  rectify.  c  The  most  common 
British  butterflies,'  it  has  been  remarked,  'most 
persons  may  have  observed  to  be  those  which  are 
white;  and  all  these  are  usually  looked  upon  as 


UNIFORM    SIZE    OF    INSECTS.  347 

of  the  same  species,  differing  in  nothing,  except, 
perhaps,  in  the  size;  the  latter  being  erroneously 
ascribed  to  difference  of  age.  But  the  fact  is,  that 
there  are  a  considerable  number  of  species  of  our 
white  butterflies,  as  well  as  several  genera,  and  pro- 
bably more  varieties  even  of  these  than  have  yet  been 
ascertained  or  described.  It  is  certain,  indeed,  that 
butterflies  do  not,  like  the  larger  animals,  increase 
in  size  as  they  grow^  older;  for  every  individual, 
from  the  moment  it  becomes  a  butterfly,  continues 
invariably  of  the  same  size  till  its  death.  Butter- 
flies, indeed,  seldom  live  longer  than  a  few  days,  or 
at  most  a  few  weeks,  and  during  this  time  they  eat 
little,  except  a  sip  of  honey:  and  since  this  is  so,  it 
would  be  absurd  to  expect  that  they  could  increase  in 
size.  '  It  must  not,  however,  be  understood  from  this, 
that  the  same  species  will  always  measure  or  weigh 
precisely  the  same;  for  though  this  will  hold  as  a 
general  rule,  there  are  many  exceptions,  arising  from 
the  accidents  the  caterpillar  may  have  suffered  from 
which  an  individual  butterfly  originated.  It  is  only 
during  the  caterpillar  state  that  the  insect  eats  vora- 
ciously, and  grows  in  proportion;  and  if  it  is,  during 
this  stage  of  its  existence,  thrown  upon  short  allow- 
ance, it  cannot  acquire  the  standard  magnitude,  and 
the  butterfly  will  be  dwarfed  from  the  first.  The 
same  remarks  with  respect  to  growth  apply  to  insects 
of  every  kind,  and  the  fact  cannot  be  better  exemplified 
than  in  the  uniformity  of  size  in  the  house  fly  (Musca 
domeslica)  among  which  scarcely  one  individual  in  a 
thousand  will  be  found  to  differ  a  hair's  breadth  in 
dimensions  from  its  fellows.'* 

We  may  add,  that  there  are  many  flies  occasion- 
ally found  in  houses  both  larger  and  smaller  than  the 
Musca  domestica,  but  these  are  of  a  different  spe- 

*  J.  Rennie  on  the  White  Butterflies  of  Britain,  Mag.  Nat. 
Hist,  vol.  ii,  p.  225. 


348  INSECT    TRANSFORMATIONS. 

cies,  and  not,  as  is  popularly  believed,  the  old  or 
the  young  of  the  house  fly;  no  more  than  The  mid- 
summer cockchafer  (Zanthcumia  solstitialis,  LEACH) 
is  the  young  of  the  common  cockchafer  (Mdolonihn 
vulgaris).  It  would  be  equally  correct  to  say  that 
an  ass  is  the  young  of  a  blood-horse,  or  a  mouse  the 
young  of  a  rat.  Nor  is  this  mistake  confined  merely 
to  popular  belief,  for  we  find  it  not  only  stated  in 
books  of  natural  history,  but  reasons  assigned  for  its 
correctness.  *  It  is  held  by  some  apiarians,'  says 
Huish,  c  that  the  bee,  in  emerging  from  its  cell,  has 
attained  its  full  growth;  I  would,  however,  recom- 
mend to  those  gentlemen  to  try  to  thrust  either  a 
bee  or  a  drone  into  one  of  the  breeding-cells,  and 
he  will  find  that  the  capacity  of  their  bodies  is  too 
large  for  the  dimensions  of  the  cell.'*  This  experi- 
ment would  not,  of  course,  succeed;  but  that  does 
not  prove  the  doctrine,  for  the  author  does  not  take 
into  consideration  the  great  quantity  of  air  by  which 
the  body  is  distended;  and  even  if  this  were  ex- 
pelled by  putting  the  bee  under  the  exhausted  receiver 
of  an  air-pump,  the  wings  and  other  parts,  now  be- 
come dry  and  rigid,  could  not  be  folded  up  in  the 
compact  manner  in  which  they  •xisted  in  the  pupa 
state. 

The  fact  of  the  expansion  of  the  wings  by  the 
impulsion  of  air  and  fluids  into  their  nervures, 
may  be  illustrated  by  the  accidental  circumstances 
into  which  chrysalides  may  fall.  We  have  men- 
tioned in  a  preceding  page,  that  the  thread  by  which 
a  chrysalis  is  suspended  may  sometimes  snap  asun- 
der. When  this  happens,  and  the  chrysalis  is  allowed 
to  remain,  it  will  not  usually  produce  an  insect  com- 
plete in  all  its  parts;  for  the  side  upon  which  it  lies 
being  pressed  against  an  unyielding  substance  by  its 
own  weight,  instead  of  hanging  lightly  suspended 

*  Huish  on  Bees,  p.  43 


DEFORMED    INSECTS.  349 

by  a  silken  cord,  is  prevented  from  becoming  duly 
expanded,  and  when  the  insect  is  excluded  it  is  found 
to  be  deformed.  This  might  by  some  be  imagined 
to  be  a  mere  theoretical  view  deduced  from  physio- 
logical reasoning;  but  we  can  prove  it  by  specimens 
of  moths  arid  butterflies  which  we  have  reared.  A 
colony  of  the  brown-tail  moth  (Porthesia  auriflua), 
which  we  reared  during  the  summer  of  1829,  spun  in 
the  corner  of  a  nurse-box  a  common  web  of  several 
chambers  for  containing  the  pupae.  One  of  these 
chambers  being  accidentally  torn,  a  pupa  fell  upon 
the  earth  in  the  bottom  of  the  box,  and  in  due  time  a 
female  moth  was  produced  from  it  ;  but  she  never 
succeeded  in  expanding  her  wings,  which  remained 
till  her  death  shrunk,  rumpled,  and  totally  useless  for 
the  purpose  of  flying,  though  in  every  other  respect 
she  was  full  grown,  and  deposited  in  the  box  a  group 
of  fertile  eggs,  covered  with  down  from  her  tail  as 
neatly  as  was  done  by  her  sisters  of  the  same  brood. 
In  the  summer  of  1825,  the  chrysalis  of  a  small  tor- 
toiseshell  butterfly  ( Vanessa  Urticce)  lost  its  hold  of 
its  silken  suspensory,  and  fell  upon  the  pasteboard 
bottom  of  a  nurse-box,  resting  in  a  sort  of  angular 
position,  so  that  the  case  of  the  upper  wing  on  the 
left  side  pressed  upon  the  box  with  the  whole  weight 
of  the  chrysalis  above  it.  When  the  butterfly  made 
its  appearance,  it  expanded  its  wings  as  usual,  but 
the  wing  upon  which  it  had  rested  was  not  half  the 
size  of  the  one  on  the  right  side  which  had  lain 
uppermost.  Another  of  the  same  brood  had  by 
some  cause  not  grown  so  large  in  the  caterpillar 
state  as  the  rest.  It  was  transformed,  notwithstand- 
ing, into  a  chrysalis,  which  appeared  healthy  and 
well  formed;  but  when  the  butterfly  appeared,  though 
it  did  not  differ  from  the  usual  appearance,  its  wings 
never  expanded  a  single  hair's  breadth,  and  remained 
VOL.  vr,  30 


350 


INSECT    TRANSFORMATIONS. 


always  in  the  same  state  as  when  it  issued  from  the 
chrysalis.* 


II 


«,  Vanessa  urtigce,  with  one  wing  imperfect.  6,  brown-tail 
moth,  Porthesia  aunjlua,  with  shrivelled  wings,  c,  Vanessa  urtic<K^ 
with  unexpanded  wings. 

It  is  not  a  little  remarkable,  that  when  insects  are 
evolved  from  the  pupa  state,  they  always  discharge 
some  substance.  It  is  important  to  remark,  that  the 
matter  voided  at  tliis  period  by  many  butterflies  ( Va- 
nessce,  &c,)  is  of  a  red  colour,  resembling  blood,  while 
that  of  several  moths  is  orange  or  whitish.  It  could 
not  readily  be  supposed  that  this  should  become  the 
object  of  superstitious  terror,  yet  so  it  has  been  in 
more  instances  than  one.  MoufFet  tells  us,  from 
Sleidan,  that  in  the  year  1 553  a  prodigious  multitude 
of  butterflies  swarmed  throughout  a  great  portion  of 
Germany,  and  sprinkled  plants,  leaves,  buildings, 
clothes,  and  men,  with  bloody  drops  as  if  it  had  rained 
blood. "f  Several  historians,  indeed,  have  recorded 
showers  of  blood  among  the  prodigies  which  have 
struck  nations  -with  consternation,  as  the  supposed 
omen  of  the  destruction  of  cities  and  the  overthrow 
of  empires.  About  the  beginning  of  July,  1608,  one 
of  these  showers  of  blood  was  supposed  to  have  fallen 


R, 


MoufTet,  Theatr.  Ins.  107. 


SHOWERS    OF    BLOOD    EXPLAINED.  351 

in  the  suburbs  of  Aix,  and  for  many  miles  around 
it,  and  particularly  the  walls  of  a  churchyard  were 
spotted  with  the  blood.  This  occurrence  would,  no 
doubt,  have  been  chronicled  in  history  as  a  super- 
natural prodigy,  had  not  Aix  possessed  at  this  time, 
in  M.  Peiresc,  a  philosopher,  who,  in  the  eager  pur- 
suit of  all  kinds  of  knowledge,  had  not  neglected  the 
study  of  insects.  It  is  accordingly  related,  in  the 
curious  life  of  Peiresc  by  Gassendi,  that  he  had, 
about  the  time  of  the  rumoured  shower  of  blood, 
happened  to  find  a  large  chrysalis,  the  beauty  of 
which  made  him  preserve  it  in  a  box.  Some  time 
after,  hearing  a  noise  in  the  box,  he  opened  it  and 
found  a  fine  butterfly,  which  had  left  upon  the  bottom 
a  red  stain  of  considerable  magnitude,  and  apparently 
of  exactly  the  same  nature  with  the  drops  on  the  stones, 
popularly  supposed  to  be  blood.  He  remarked,  at 
the  same  time,  that  there  were  countless  numbers  of 
butterflies  flying  about,  which  confirmed  him  in  the 
belief  of  his  having  discovered  the  true  cause  ;  and 
this  was  further  corroborated  by  his  finding  none  of 
the  red  drops  in  the  heart  of  the  city,  where  the  butter- 
•  flies  were  rarely  seen.  He  also  remarked,  that  the 
drops  were  never  on  tiles,  and  seldom  on  the  upper 
part  of  a  stone,  as  they  must  have  been  had  they 
fallen  from  the  heavens,  but  usually  appeared  in 
cavities  and  parts  protected  by  some  angular  projec- 
tion. What  Peiresc  had  thus  ascertained,  he  lost 
no  time  in  disclosing  to  many  persons  of  knowledge 
and  curiosity,  who  had  been  puzzling  themselves  to 
account  for  the  circumstance  by  far-fetched  reason- 
ings, such  as  a  supposed  vapour  which  had  carried 
up  a  supposed  red  earth  into  the  air  that  had  tinged 
the  rain  ;  —  no  less  wide  of  the  truth  than  the  popular 
superstition  which  ascribed  it  to  magic,  or  to  the 
devil  himself*  Those  who  are  curious  to  verify  the 

*  Reaumur,  vol.  i,  p.  638. 


352  INSECT    TRANSFORMATIONS. 

discovery,  as  we  may  well  call  it,  of  Peiresc,  may 
easily  do  so  by  rearing  any  of  the  spinous  caterpillars 
which  feed  on  the  nettle  till  they  are  transformed  into 
the  butterfly.  We  have  witnessed  the  circumstance 
in  innumerable  instances. 

It  is  a  curious  and  interesting  probability,  that  the 
crimson  snow  of  the  Alpine  and  Arctic  regions,  which 
has  recently  excited  so  much  scientific  inquiry,  should 
be  referable  to  a  somewhat  similar  cause,  —  a  circum- 
stance which  will  apologize  for  our  taking  some  no- 
tice of  it  here  by  way  of  illustration.  According  to 
Professor  Agardh,  red  snow  is  very  common  in  all 
the  alpine  districts  of  Europe,  and  is  probably  of  the 
same  nature  with  that  brought  from  the  polar  regions 
by  Captain  Ross.  Saussure  saw  it  in  abundance  on 
Mont  Brevern,  in  Switzerland,  and  elsewhere  ; 
Ramond  found  it  on  the  Pyrenees  ;  and  Sommerfeldt 
in  Norway.  In  March,  1808,  the  whole  country 
about  Cadone,  Belluno,  and  Eeltri,  is  reported  to 
have  been  covered  in  a  single  night  with  rose-coloured 
snow  ;  and  at  the  same  time  a  similar  shower  was 
witnessed  on  the  mountains  of  Valtelin,  Brescia, 
Carinthia,  and  Tyrol.  But  the  most  remarkable  red 
snow"  shower  was  that  which  fell  on  the  night  between 
the  14th  and  loth  of  March,  1823,  in  Calabria, 
in  Abruzzo,  in  Tuscany,  at  Bologna,  and  through  the 
whole  chain  of  the  Appennines. 

Upon  the  return  of  Captain  Ross  from  the  Polar 
expedition  some  years  ago,  the  specimens  of  red 
snow  which  he  brought  home  were  examined  by 
three  of  our  most  distinguished  observers,  Wollaston, 
Bauer,  and  Robert  Brown,  who  all  came  to  the 
conclusion  that  it  was  of  a  vegetable  nature,  but 
differed  as  to  its  botanical  characteristics.  Dr 
Wollaston  supposed  it  to  be  the  seed  of  some  moss  ; 
Mr  Brown  was  inclined  to  consider  it  an  algas,  re- 
lated to  Tremella  cruenia,  a  common  native  plant  ; 


CAUSE    OF    RED    SNOW.  353 

while  Mr  Bauer  thought  it  was  a  fungus  of  the  genus 
Uredo.  Professor  Agardh  refers  it  with  Brown  to 
the  lowest  order  of  algae,  but  standing  as  a  distinct 
genus  upon  the  very  limits  of  the  animal  and  vegeta- 
ble kingdoms.  Saussure,  indeed,  from  finding  that 
the  red  snow  of  the  Alps  gave  out,  when  burnt,  a 
smell  like  that  of  plants,  concluded  that  it  was  of 
vegetable  origin,  and  supposed  it  to  consist  of  the 
farina  of  some  plant,  though  he  could  not  trace  it  to 
its  source.  Baron  Wrangel,  again,  who  discovered  a 
production  similar  or  identical  with  Agardh's  Proto- 
coccus  nivalis  growing  upon  limestone  rocks,  mentions 
that  it  was  easily  detached  when  placed  under  water, 
and  in  three  days  it  was  converted  into  animated  globules 
like  infusory  animalcules,  which  swam  about  and  were 
made  prey  of  by  other  infusoria.  Professor  Nees  von 
Esenbeck  of  Bonn,  is  inclined  to  think  that  the  minute 
red  globules,  of  which  the  Protococcus  consists,  are  the 
vegetable  state  of  bodies  which  had  gone  through  a 
previous  animal  existence. 

The  Rev.  W.  Scoresby,  on  the  other  hand,  conjec- 
tures that  the  red  colour  of  the  snow  may  be  traced  to 
the  same  cause  as  the  orange-coloured  ice  of  the  polar 
seas,  which  arises  from  innumerable  minute  animals 
belonging  to  the  Radiata,  and  similar  to  the  Beroe 
globidosa  of  Lamarck.  It  is  about  the  size  of  a  pin's 
head,  transparent,  and  marked  with  twelve  brownish 
patches  of  dots.  In  olive-green  sea  water,  he  esti- 
mated 1 10,592  of  these  in  a  cubic  foot.* 

Agardh  remarks,  that  it  is  agreed  upon  all  hands 
that  the  crimson  snow  always  falls  in  the  night,  from 
which  he  infers  that  it  has  not  been  actually  seen  to 
fall.  He  thinks  it  is  called  into  existence  by  the 
vivifying  power  of  the  sun's  light,  after  its  warmth  has 
caused  the  snow  to  dissolve,  accompanied  by  the 

*  Jameson's  Edin.  Journ.,  Jan,  1829,  p.  55. 
VOL.  vi.  30* 


354  INSECT    TRANSFORMATIONS. 

incomprehensible  power  in  white  snow  of  producing  a 
colour.* 

Reaumur  says,  with  much  justice,  on  another  oc- 
casion, that  an  ordinary  spectator  frequently  discovers 
what  has  escaped  the  notice  of  the  best  observers, 
and  so  it  should  seem  it  has  happened  in  the  present 
case, — the  learned  naturalists  just  mentioned  having 
gone  as  wide  of  the  facts,  as  the  philosophers  at  Aix 
in  accounting  for  the  supposed  shower  of  blood.  Mr 
Thomas  Nicholson,  accompanied  with  two  other  gen- 
tlemen, made  an  excursion  the  24th  July,  1821,  to 
Sowallick  Point,  near  Bushman's  Island,  in  Prince  Re- 
gent's Bay,  in  quest  of  meteoric  iron.  '  The  summit 
of  the  hill,'  he  says,  c forming  the  point,  is  covered  with 
huge  masses  of  granite,  whilst  the  side  which  forms  a 
gentle  declivity  towards  the  bay  was  covered  with  crim- 
son snow.  It  was  evident,  at  first  view,  that  this  co- 
lour was  imparted  to  the  snow  by  a  substance  lying  on 
the  surface.  This  substance  lay  scattered  here  and 
there  in  small  masses,  bearing  some  resemblance  to 
powdered  cochineal,  surrounded  by  a  lighter  shade, 
which  was  produced  by  the  colouring  matter  being 
partly  dissolved  and  diffused  by  the  deliquescent  snow. 
During  this  examination  our  hats  and  upper  garments 
were  observed  to  be  daubed  with  a  substance  of  a  simi- 
lar red  colour,  and  a  moment's  reflection  convinced  us 
that  this  was  the  excrement  of  the  little  auk  ( Uria  alle, 
TEMMINCK),  myriads  of  which  were  continually  flying 
over  our  heads,  having  their  nests  among  the  loose 
masses  of  granite.  A  ready  explanation  of  the  origin 
of  the  red  snow  was  now  presented  to  us,  and  not  a 
doubt  remained  in  the  mind  of  any  that  this  was  the 
correct  one.  The  snow  on  the  mountains  of  higher 
elevation  than  the  nests  of  these  birds  was  perfectly 
white,  and  a  ravine  at  a  short  distance,  which  was  filled 
with  snow  from  top  to  bottom,  but  which  afforded  no 

*  London's  Encycl,  of  Plants,  Protococcus. 


CAUSE    OF    RED    SNOW.  355 

hiding-place  for  these  birds  to  form  their  nests,  pre- 
sented an  appearance  uniformly  white.'* 

This  testimony  seems  to  be  as  clear  and  indisputable 
as  the  explanation  given  by  Peiresc  of  the  ejecta  of  the 
butterflies  at  Aix.  But  though  it  will  account,  per- 
haps, for  the  red  snow  of  the  polar  regions,  it  will  not 
explain  that  of  the  Alps,  the  Appennines,  and  the  Py- 
renees, which  are  not,  so  far  as  we  know,  visited  by 
the  little  auk.  Thus  the  matter  at  present  rests,  till 
it  be  elucidated  by  further  observations. 

*  Mag.  of  Nat.  Hist.,  vol.  ii,  p.  322. 


CHAPTER  XV. 


Peculiar  Motions  of  Insects. 

NOTHING  that  has  life  seems  capable  of  existing 
long  without  motion.  The  oyster  fixed  upon  the  rock 
must  open  and  shut  its  shell,  and  the  most  gnarled  oak 
must  wave  its  branches, otherwise  their  fluids  will  stag- 
nate, and  disease  will  ensue.  In  our  own  case,  we 
cannot,  if  we  would,  put  a  stop  for  any  length  of  time 
to  all  our  motions.  We  have  the  power,  indeed,  of 
interrupting  the  nictitation  of  the  eyelids;  but  if  we  keep 
our  eyes  fixed  for  a  few  minutes  they  become  dry  and 
painful  for  want  of  the  regular  supply  of  moisture  spread 
over  them  by  the  process  of  winking.  Breathing, again, 
being  a  more  important  operation,  cannot  be  long  in- 
terrupted, without  serious  consequences;  and  when  the 
motion  of  any  of  the  limbs  is  prevented  by  the  acci- 
dental injury  of  its  joint,  it  usually  shrinks  and  dwin- 
dles into  less  than  half  its  natural  magnitude,  because 
the  proper  quantity  of  the  nutritive  fluids  is  not  impelled 
thither  in  consequence  of  its  deficiency  of  motion. 

We  have  already  seen  how  indispensable  the  motions 
of  insects  are  to  the  due  expanding  of  their  wings  upon 
emerging  from  the  pupa  state;  and  several  remarkable 
circumstances  show  that,  independent  of  change  of 
place  in  search  of  food  or  of  other  localities  for  their 
progeny,  motion  is  necessary  to  their  well-being.  At 
least  there  does  not  seem  any  other  plausible  explication 
of  what  we  may  term  stationary  motions.  Kirby  and 
Spence's  c  motions  of  insects  reposing,'*  appears  to  be 
a  phrase  which  would  not  apply,  for  example,  to  an  ox 
chewing  the  cud,  or  a  cat  washing  her  face  with  her  paw, 
— motions  precisely  similar  to  many  of  those  of  insects 

*  Introd.  vol.  ii,  p.  304. 


MOTIONS    OF    INSECTS.  357 

mentioned   by   them  under  this  head.      The   mode 
adopted  by  cats  of  cleaning    themselves  with  their 
paws,  is,  indeed,  not  a  little  similar  to  that  of  the 
house  fly  (Musca  domestica),  which,  while  it  is  bask- 
ing in  a  window  and  enjoying  the  heat  of  the  sun, 
may   be    frequently    seefi  not  only  brushing  its  feet 
upon  one  another  to  rub   jff  the  dust,  but  equally 
assiduous  in  cleaning  its  eyes,  head,  and  corslet  with 
its  fore-legs,  while  it  brushes  its  wings  with  its  hind- 
legs.*     At  the  time  of  writing  this,  March,  1830, 
we  have  just  witnessed  a  similar  process  in  a  water 
measurer   (Hydrometra  stagnorum,   LATR.),    which 
we   had   put   into  a  glass  containing  water,  with  a 
leaf  for  it  to  rest  upon.     Not  liking  the  narrow  pool 
in  the  glass  so  well  as  the  brook  at  Lee,  from  which 
it  had  been  taken,  it  began  to  climb  the  edges  of  the 
glass,   for    which    its  feet  were  far  from  being  well 
adapted,  and    it    slipped   at  every  step  ;  but,  deter- 
mined not  .to  be  baulked,  after  several  unsuccessful 
trials,  it  betook  itself  to  the  leaf  as  if  to  survey  the 
obstacles  before  it  again  attempted  the  steep  ascent. 
After  deliberating  for  a  moment,  the  thought  seemed 
to  strike  it  that  its  feet  were  not  in  the  best  trim  for 
climbing  ;  and  it  forthwith  began  with  great  assiduity 
to  clean  them  somewhat  in  a  similar  way  to  the  fly 
by  wiping  them  upon  one  another,  but  with  this  dif- 
ference, that  it  did  not,  like  the  fly,  cross  its  legs  from 
opposite  sides,  the  length  and  rigidity  of  the  thighs 
preventing  such  a  movement.     It  did  not  forget  at 
the  same  time  to  clean  with  much  care  its  long  an- 
tennae, in  order,  no  doubt,  to  fit  them  the  better  for 
exploring  an  unknown  path.     It.  spent  several  mi- 
nutes in  this  preliminary  trimming,  when  it  again  be- 
gan to  mount,  and  we  were  no  less  pleased,  perhaps, 
than   itself,   to    see  its  perseverance  rewarded  ;  for, 
aided  either  by  the  greater  cleanness  of  its  feet,  or  by 

*  See  Insect  Architecture,  p.  368. 


358  INSECT    TRANSFORMATIONS. 

some  particles  of  slime  and  sand  adhering  to  the 
glass,  it  triumphantly  gained  the  brim,  which  it  began 
to  perambulate  with  an  apparent  air  of  proud  exul- 
tation.* This  insect  is  figured  at  6,  page  382. 

The  process  of  cleaning  and  brushing  the  legs,  as 
birds  are  seen  to  preen  their  feathers,  is,  however, 
the  most  remarkable,  though,  perhaps,  but  seldom 
taken  notice  of  among  spiders.  The  same  process,  as 
we  have  recently  discovered,  is  employed  by  the  Pha- 
langia.  The  apparatus  for  this  is  admirably  con- 
trived. In  the  common  garden  geometric  spider 
(Epeira  diadem*),  the  teeth  are  used  as  a  comb, 
the  smooth  mandible  being  employed  to  hold  down 
the  limb  while  it  is  slowly  drawn  between  the  teeth, 
to  free  it  from  flue  and  dust.  In  some  other  species, 
instead  of  smooth  teeth,  there  is  a  thick-set  brush 
of  hairs,  which  is  used  in  the  same  manner,  and 
must  be  a  still  more  efficient  instrument.  The  former, 
if  we  do  not  mistake,  chiefly  occurs  among  the 
geometric  spiders,  whose  webs  are  meshed  and  thin  ; 
while  the  brush  prevails  among  those  which  weave 
thick  webs,  such  as  the  red  spider  (Dysdera  ery- 
thrina,  WALCKENAER),  which  we  found  in  the  cre- 
vice of  a  chalk  rock  near  Erith,  in  Kent,  but  which  is 
by  no  means  common  in  Britain,  though  abundant  in 
France.  We  kept  this  one  for  some  time  in  a  glass, 
and  observed  that  it  spent  the  greater  part  of  its 
time  in  brushing  its  legs.  The  eyes  are  placed  in 
form  of  a  horse-shoe. | 

It  must  have  struck  those  who  have  visited  a 
menagerie  of  wild  animals,  that,  even  while  they  are 
standing  in  their  cages,  they  frequently  throw  their 
heads,  and  also  their  bodies,  into  a  sort  of  oscillatory 
movement,  evidently  not  for  the  purpose  of  getting 
through  the  bars,  but  to  supply  the  place  of  their 
natural  exercise  which  confinement  prevents  them 

*J.  R.  tj.  R. 


MOTIONS    OP    INSECTS. 


359 


a,  red  spider  (Dysdera  erythrina').  &,  the  head  of  the  red 
spider,  magnified  c  c,  the  mandibles,  fringed  on  the  inside  with 
hair,  d,  the  eight  eyes,  in  form  of  a  horse-shoe,  e,  the  head  of 
the  garden  spider  (Aranea  diadtma).  f  f  f,  the  eight  eyes- 

g  g-,  the  upper  mandibles.    A,  toothed  comb. 

from  taking.  Perhaps  this  may  help  us  to  account 
for  the  singular  motions  of  some  of  the  crane  flies 
(Tipulidce),  while  stationary  upon  a  window  or  a 
wall,  their  whole  body  vibrating  alternately  outwards 
and  inwards  from  the  wall,  with  a  pendulum-iike 
movement,  as  rapid,  or  more  so,  than  the  clicking  of 
a  watch.  Kirby  and  Spence  say,  this  is  produced  by 
the  weight  of  their  bodies  and  the  elasticity  of  their 
legs;  and  that,  unless  it  be  connected  with  respira- 
tion, it  is  not  easy  to  say  what  is  its  object.*  To  us 
it  appears,  like  the  motion  of  the  caged  animals  just 
mentioned,  to  be  for  the  purpose  of  exercising  them- 
selves and  of  driving  the  fluids  into  their  long  legs, 
which  may  not  be  effected  in  the  exercise  of  flying  on 
account  of  their  legs  then  remaining  almost  motion- 
less. Others  of  the  same  family  may  be  seen  hang- 
ing from  a  wall  or  ceiling  by  their  fore-legs,  while  the 
hind  ones  are  perked  out  into  the  air,  and  moving  up 
and  down  in  a  slow  manner,  probably  to  watch  against 
approaching  danger,  as  they  are  very  timid;  and  if 
the  door  of  the  room  where  they  are  be  hastily  opened 
or  shut,  or  if  any  other  agitation  of  the  air  be  pro- 

*  Intr.  ii,  306. 


360 


INSECT    TRANSFORMATIONS. 


ducedj  they  immediately  fly  off.*  The  long-legged 
spiders,  popularly  called  shepherds  and  harvest  men 
(Phalangidce,  LEACH),  have  a  similar  mode  of  ele- 
vating their  legs,  particularly  the  second  pair,  which 
they  move  about  in  all  directions. 


«,  Phalangium  }  b,  Hydrometra  stagnorum,  magnified. 

It  can  scarcely  have  escaped  the  remark  of  the 
most  indifferent  observer,  that  when  butterflies  (par- 
ticularly those  of  the  genus  Vanessa]  alight  during 
sunshine  on  a  leaf  or  a  pathway,  they  flirt  their 
wings  as  a  lady  does  her  fan,  and  perhaps,  as  has 
been  conjectured,  for  the  similar  purpose  of  cooling 
their  bodies.  But  to  us  it  appears  more  probably  with 
the  design  of  impelling  air  into  the  tubes  of  their 
wings  to  fit  them  the  better  for  flight  ;  for  we  have 
remarked  that  they  uniformly  fan  their  wings  when 
about  to  rise,  though  they  had  previously  remained 
motionless  for  an  hour  together.  A  pretty  family  of 
two-winged  flies  (Syrphidce^)  may  frequently  be 
remarked  in  lanes  and  on  the  borders  of  woods, 
hovering  on  the  wing  for  a  considerable  time  without 
shifting  a  hair's-breadth  from  their  place,  though  the 
motion  of  their  wings  is  all  the  while  so  rapid  as  to 
be  almost  imperceptible,  similar  to  some  moths 
(Sphingidce,  Plusia  gamma  £  &c,)  whilst  sipping 


J.  R. 


t  See  p.  4. 


See  p.  214. 


MOTIONS    OF    OTHER    ANIMALS.  361 

the  honey  of  flowers.  The  vibratory  motion  of  the 
wings  in  these  instances  is  only  to  buoy  them  up  so 
as  to  retain  their  place  ;  but  the  instant  they  are 
alarmed  by  the  approach  of  danger,  they  may  be 
seen  to  take  several  long  strokes  with  their  wings, 
and  dart  off  with  the  rapidity  of  lightning.  This  is 
well  illustrated  by  the  motions  of  birds  preparatory 
to  flight,  as  they  may  be  observed  always  to  take  se~ 
veral  deep  inspirations,  at  the  same  time  often  rising  on 
tiptoe,  and  puffing  out  and  balancing  their  bodies  to 
feel  whether  they  have  thrown  enough  air  into  their 
bones  and  feathers  to  float  them  along.  Birds  of  prey 
(Raptores,  VIGORS)  seem  to  have  the  greatest  power 
both  of  filling  their  bodies  with  air  and  of  expelling  it 
again  at  pleasure.  Hence  the  kestril  (Falco  tinnun- 
culus)  may  be  seen  floating  about  for  a  considerable 
time  without  moving  a  wing,  or  perhaps  drawing  a 
breath,  till  it  can  hold  out  no  longer,  when  it  flutters  its 
wings  rapidly,  not  for  moving  to  a  different  place,  for 
it  remains  stationary,  but  to  recover  its  decreasing 
buoyancy  by  inhaling  a  fresh  supply  of  air.  For  the 
same  reason  a  trout  will  oscillate  its  body  when  losing 
ground  by  the  rapidity  of  a  stream.  The  osprey  (Falco 
ossifragus\  on  the  other  hand,  we  have  seen,  at  the 
Kyles  of  Bute  and  elsewhere,  shoot  down  like  a  thun- 
derbolt from  the  air  into  the  sea,  plunging  far  into  the 
water  upon  a  fish  she  had  marked  for  her  prey,*  —  a 
movement  only  to  be  explained  by  the  rapid  expulsion 
of  the  air  which  had  been  the  chief  agent  in  keeping  her 
previously  afloat  in  the  region  of  the  clouds.  Many 
birds  which  prey  on  smaller  game  have  somewhat  simi- 
lar methods  of  poising  and  balancing  their  bodies,  of 
which  the  water-ouzel  ( Cinclus  aquations,  BECHSTEIN) 

*  'Super  est  Halteetos,'  says  Pliny,  «  clarissima  oculorum 
acie,  librans  ex  alto  sese,  visoque  in  mari  pisce,  prasceps  in  eurn 
ruens,  et  discussia  aquis,  rapiens.' —  Hist.  JYat. 

VOL.  VI.  31 


362  INSECT    TRANSFORMATIONS. 

furnishes  a  good  example,  putting  itself  in  a  constant 
state  of  preparation,  jerking  its  piebald  head  up  and 
down  as  it  skips  from  stone  to  stone  of  the  brook,  to 
pounce  under  water  upon  the  first  grub  it  espies  swim- 
ming. In  the  same  way  the  red-breast  (Sylvia  rube- 
cula)  pops  jerking  about  when  on  the  look-out  for  ca- 
terpillars; and  so  habitual  does  this  become,  that  he 
does  not  fail  to  go  through  the  mano3uvre  when  he 
pecks  up  a  crumb  at  the  cottage  door,  as  well  as  when 
he  pounces  upon  a  caterpillar  in  the  woods,  where  it  is 
often  indispensable  to  secure  the  aim  to  prevent  the 
insect  putting  in  force  some  stratagem  of  escape.* 

We  may  next  turn  to  a  small  two-winged  fly,  which, 
though  equally  common  in  gardens  and  elsewhere  with 
the  fanning  butterflies  (Vanessce)  just  alluded  to,  we 
can  scarcely  (considering  its  size)  expect  to  have  at- 
tracted the  notice  of  those  who  pay  little  attention  to 
insects.  We  allude  to  the  vibrating  fly  ( Seioptera  m- 
brans,  KIRBY),  which  is  not  above  a  third  of  the  size 
of  the  house-fly,  but  may  be  known  by  its  shining  black 
body,  scarlet  head,  and  transparent  wings,  tipped  with 
black.  This  tiny  little  creature  whether  it  trips  over 
a  leaf,  or  remains  stationary  basking  in  the  sunshine,  is 
continually  vibrating  its  wings.  <  This  motion,'  says 
Kirby,  '  I  have  reason  to  think,  assists  its  respiration;' 
but  as  he  has  not  stated  his  reason,  we  are  led,  from 
an  experiment  which  we  tried,  to  doubt  the  conclusion. 
Having  always  seen  the  fly  vibrating  its  wings  in  the 
sunshine  only,  as  if  it  enjoyed  the  warmth  and  rejoiced 
in  the  feeling  of  existence,  we  wished  to  see  how  it 
would  comport  itself  at  night,  and  enclosed  one  under 
an  inverted  wine-glass  for  observation.  The  conjec- 
ture which  we  had  formed  appeared  to  be  correct;  for 
though,  when  moving  about  the  glass,  it  vibrated  its 

*  J,  R. 


MOTIONS    OF    INSECTS.  363 

wings  as  much  by  candle-light  as  in  the  sunshine,  pro- 
bably from  the  habit  of  associating  the  two  movements, 
yet,  whenever  it  remained  stationary,  it  kept  the  wings 
motionless.  Had  the  motion  been  indispensable  to  re- 
spiration, and  analogous  to  the  motion  of  the  gills  of 
fish,  or  the  panting  in  the  anal  scale  of  the  water-louse, 
(Jlscllus  aquaticuSj  LEACH),  this  cessation  would  not 
have  taken  place  at  night. 

We  are,  therefore,  perhaps  justified  in  concluding 
that  the  vibration  of  the  wings  in  this  little  fly  is  an 
indication  of  being  pleased  ;  in  the  same  way  as  a 
nestling  sparrow,  when  fed  by  its  dam,  will  half  stretch 
its  wings,  and,  as  Thompson  finely  expresses  it;  will 

'  Quiver  every  feather  with  desire;* 

or  as  a  lamb  when  sucking  will  vibrate  its  tail,  as  well 
as  the  pretty  birds  popularly  termed  wagtails  (Mola- 
ct//ce),  when  they  perambulate  the  margin  of  a  stream 
and  find  a  plentiful  banquet  of  insects  to  their  liking. 

It  may  prove  still  more  interesting,  we  think,  to 
turn  our  attention  to  some  other  movements  of  insects 
which  seem  to  be  expressive  of  pleasure  when  they  are 
not  stationary,  and  leaving  out  of  consideration,  also, 
their  foraging  for  food.  A  familiar  instance  of  what 
we  allude  to  occurs  in  the  aerial  dances  of  the  tipuli- 
dan  gnats  and  some  other  insects.  These  are  per- 
formed not  only  in  summer,  but  frequently  even  in 
winter,  and  in  the  early  months  of  spring, —  in  shelter- 
ed places,  indeed,  such  as  under  trees  and  hedges,  in 
lanes,  and  when  a  day  chances  to  be  finer  than  usual, 
though  the  mildest  day  is  of  course  at  these  seasons 
comparatively  chill.  The  most  common  of  these  win- 
ter dancers  is  called  by  Harris  the  tell-tale  (Tricho- 
cera  hiemalis,  MEIGEN),  a  troop  of  which  may  be 
occasionally  seen  gamboling  in  a  sunny  nook,  though 
the  ground  be  covered  with  snow.  When  the  weather 


364  INSECT    TRANSFORMATIONS. 

is  warm  and  mild,  however,  the  dancing  Tipulidce  pre- 
fer the  decline  of  day;  and  wo  have  remarked  them 
keeping  it  up  as  long  as  we  could  distinguish  them 
between  the .  eye  and  the  waning  light  of  the  western 
horizon:  how  much  longer  they  continued  to  dance 
we  cannot  tell. 

It  is  a  very  singular  fact  connected  with  these  gnat 
dances,  that  the  company  always  consists  exclusively 
of  males.  This  any  person  who  will  take  the  trouble 
may  verify  by  enclosing  a  group  of  them  in  a  butterfly- 
net.  If  this  be  not  at  hand,  he  may  procure  good  evi- 
dence by  wetting  the  hand,  and  passing  it  quickly 
amongst  the  thickest  of  the  crowd;  when  several  will 
be  caught,  and  will  uniformly  exhibit  the  beautifully 
fringed  or  plumed  antennae,  which  in  the  female  are 
without  the  hairs  or  the  plumelets.  What  it  may  be, 
besides  the  same  delighted  and  buoyant  spirit  which 
causes  lambs  to  group  together  in  their  frolics,  that  in- 
duces those  tiny  gnats  to  sport  in  this  manner  on  the 
wing,  is,  perhaps,  inexplicable. 

Wordsworth's  opinion,  though  adopted  by  Kirby 
and  Spence,  is,  perhaps,  as  we  shall  presently  endea- 
vour to  show,  more  poetical  than  correct.  His  words 
are: — 

*  Nor  wanting  here  to  entertain  the  thought, 
Creatures  that  in  communities  exist, 
Less,  as  might  seem,  for  general  guardianship, 
Or  through  dependence  upon  mutual  aid, 
Than  by  participation  of  delight, 
And  a  strict  love  of  fellowship  combined. 
What  other  spirit  can  it  be  that  prompts 
The  gilded  summer  flies  to  mix  and  weave 
Their  sports  together  in  the  solar  beam, 
Or,  in  the  gloom  and  twilight,  hum  their  joy.' 

The  Excursion. 

The   evening   gamboling  of  rooks   on   the   wing, 


MOTIONS    OF    INSECTS.  365 

when  they  return  from  their  more  distant  excursions 
during  the  autumn,  rnay  with  more  certainty  be  re- 
ferred to  this  cause.  White  says,  they  rendezvous 
by  thousands  over  Selborne  Down,  wheeling  round 
and  diving  in  a  playful  manner  in  the  air,  and  when 
this  ceremony  is  over,  with  the  last  gleam  of  light, 
they  retire  to  the  deep  beech  woods  of  Tisted  and 
Kepley.  It  may  not  be  improper,  however,  to  dis- 
tinguish between  this  and  the  restless  tossing  about 
and  flapping  of  the  wings,  often  exhibited  by  rooks 
previous  to  a  storm,  which  more  usually  occurs  in  the 
morning,  and  closely  resembles  the  tossing  of  sea- 
birds  on  the  billows  during  a  gale.* 

The  quickness  of  the  vision  of  tipulidan  gnats,  and 
the  rapiclity  as  well  as  the  dexterity  of  their  motion, 
may  be  considered  not  a  little  remarkable,  from  the 
circumstance  of  their  flying  unwetted  in  a  heavy  show- 
er of  rain,  whose  drops  —  bigger  than  their  own  bo- 
dies —  if  they  fell  upon  them,  must  dash  them  to  the 
ground  ;"f*  unless  it  may  be  that  the  drops  glide  off 
their  wings  as  they  do  off  the  feathers  of  a  duck,  while 
the  elasticity  of  their  bodies  may  save  them  from  ac- 
cidents, even  when  they  chance  to  be  pelted. 

A  very  pretty  species  of  these  choral  flies  (  Chiro- 
nomus  aterrimus  ME i GEN),  is  exceedingly  common 
in  the  vicinity  of  London,  appeari-ng  about  the  close 
of  winter,  and  readily  distinguished .  by  its  shining 
snow-white  wings,  rendered  more  conspicuous  by  the 
contrast  of  its  black  body,  while  the  male  has  his 
antennae  adorned  with  beautiful  lead-gray  plumelets. 
Though  groups  of  these  may  be  found  sporting  on 
the  borders  of  woods  and  near  water,  even  in  January, 
proving  that,  though  not  half  the  size  of  the  common 
gnat  (Culex  pipiens),  they  can  brave  the  bleak  winds 
of  winter,  —  yet  they  often  crowd  into  our  apartments, 
like  many  others  of  the  family.  We  have  just  been 

*  J.  R.         t  Kirby  and  Spence,  vol.  ii,  p.  374. 
VOL.  vi.  31* 


366  INSECT    TRANSFORMATIONS. 

watching  the  proceedings  of  a  pair  of  these  elegant 
little  creatures  by  candle-light,  when  they  are  more 
lively  and  alert  than  in  the  sunshine.  We  were 
reading  a  large  quarto  book  with  wide  print  and  very 
broad  margins,  the  white  colour  of  which  seemed  not 
only  to  attract  but  to  deceive  them  in  the  same  way 
as  a  bird  or  a  blow-fly  will  mistake  a  pane  of  glass 
for  the  (  viewless  air,'  and  dash  recklessly  against 
it.  Our  little  snowy -winged  flies,  apparently  from  a 
similar  mistake,  dashed  themselves  about  on  the 
pages  of  the  book.  We  have  been  accustomed,  from 
boyhood,  to  see  gnats  and  other  insects  tumbling 
about  in  a  similar  manner  when  we  have  been  read- 
ing at  night,  a  circumstance  which  few  of  our  readers 
can  have  failed  to  observe;  but  we  always  pitied  them 
on  the  supposition  that  it  was  in  consequence  of  their 
heedlessly  singeing  their  wings  in  the  candle,  and 
thus  unfitting  themselves  to  fly.  This,  no  doubt,  is  a 
frequent  cause  of  their  falling  on  a  book;  but  it  was 
not  so  with  the  two  flies  which  we  observed,  for  they 
remained  quite  perfect  and  uninjured.  The  most 
remarkable  circumstance  was,  that  they  almost  uni- 
formly fell  on  the  back,  which  seems  to  indicate  that 
they  fly  with  the  back  downwards,  a  mode  of  flight 
not  a  little  singular,  though  it  has  an  analogy  to  the 
swimming  of  some  aquatic  insects  Notonectidce, 
LEACH).  When  they  felt  the  paper,  they  spun  round 
in  circles  and  half  circles  with  great  rapidity,  and 
evidently  not  so  much  for  the  purpose  of  getting 
upon  their  feet  as  of  continuing  the  gyrations  they 
had  been  performing  while  on  the  wing.  This  we  in- 
ferred from  their  being  in  no  hurry  to  get  up,  and 
from  their  continuing,  even  when  they  got  upon  their 
feet,  to  wheel  round  and  round,  as  if  waltzing  with 
the  express  design  of  showing  that  they  could  dance 
on  the  *  light  fantastic  toe,'  as  well  as  on  the  wing. 
Their  circular  movement  is  not  peculiar  to  them, 


MOTIONS    OF    INSECTS.  367 

being  observable  in  several  others  of  the  family,  par- 
ticularly in  a  still  smaller  fly  with  black  pellucid  wings 
(Molobrusl)y  and  not  uncommon  in  summer,  whose 
extremely  rapid  motion  we  have  often  admired  as  it 
performs  its  minute  gyrations  on  a  leaf  or  the  petal  of 
a  flower. 

It  was  no  less  remarkable,  that  the  two  snowy- 
winged  gnats  just  mentioned  were  male  and  fe- 
male, as  the  latter  is  seldom  seen,  and  when  the 
males  swarm  upon  a  window,  a  single  female  can 
scarcely  be  found;  but  though  they  were  flirting 
about  on  the  same  page,  they  took  not  the  slightest 
notice  of  one  another,  and  each  went  through  its 
gyrations  as  if  unconscious  of  the  other's  presence. 
The  female,  besides,  contrary  to  what  is  usual  among 
insects,  was  by  far  the  most  alert  and  agile  of  the 
two;  in  so  much  that,  though  it  was  early  in  March, 
we  at  first  mistook  her  for  the  minute  summer  fly  al- 
luded to  in  last  paragraph.* 

From  all  we  have  observed,  we  think  it  probable, 
that  notwithstanding  the  apparent  sociality  of  the 
dancing  gnats  (Tipulidce),  they  do  not  congregate 
in  consequence  of  any  gregarious  feelings,  or  for 
mutual  assistance;  but  merely  because  they  are  pro- 
duced in  numbers  in  the  same  places,  and  individually 
prefer  similar  haunts.  The  individual  sportive  move- 
ments of  the  two  snowy-winged  flies  just  described, 
which  were  performed  on  the  contiguous  pages  of  a 
book,  or  severally  at  the  top  and  bottom  of  the  same 
page,  prove  that  they  do  not  consider  the  presence 
of  numbers  indispensable.  This  position  is  farther 
illustrated  by  the  proceedings  of  an  insect  of  a  very 
different  family  —  the  whirlwig  beetles  (Gyrinidce, 
LEACH),  which  may  be  seen  on  the  surface  of  every 
pool  weaving  their  eccentric  dances,  and  twinkling 
their  polished  corselets  in  the  sun,  both  in  summer 
and,  as  we  have  remarked,  throughout  the  winter. 

*  J.  R. 


368  INSECT    TRANSFORMATIONS. 

These  are  most  frequently  observed  frolicking  in 
parties  of  from  two  to  a  dozen  or  more;  but  we 
have  very  frequently  seen  an  individual  performing 
his  gyrations  with  the  same  alacrity  when  alone  .as 
when  mingling  with  his  companions.  We  conclude, 
therefore,  that  the  apparent  sociality  of  these  insects 
has  no  closer  bond  than  that  of  the  vultures  which 
crowd  to  devour  the  same  carcase,  or  of  the  unsocial 
sea-birds  which  congregate  near  a  shoal  of  fish.* 

Kirby  and  Spence  appear  to  be  of  a  different 
opinion: — these  c  little  beetles,'  say  they,  '  which 
may  be  seen  clustering  in  groups  under  warm  banks 
in  every  river  and  every  pool,  and  wheeling  round 
and  round  with  great  velocity;  at  your  approach 
dispersing  and  diving  under  water,  but,  as  soon  as 
you  retire,  resuming  their  accustomed  movements,  — 
seem  to  be  under  the  influence  of  the  social  principle, 
and  to  form  their  assemblies  for  no  other  purpose 
than  to  enjoy  together  in  the  sun-shine  the  mazy 
dance. 'f 

The  following  account  of  the  manners  of  this  bee- 
tle, by  Mr  Knapp,  is  well  worth  extracting;  though 
it  is  much  more  lively  and  interesting  than  strictly 
correct : 

c  Water,  quiet,  still  water,  affords  a  place  of  action 
to  a  very  amusing  little  fellow  ( Gyrinus  natator), 
which,  about  the  month  of  April,  if  the  weather  be 
tolerably  mild,  we  see  gamboling  upon  the  surface 
of  the  sheltered  pool;  and  every  schoolboy,  who  has 
angled  for  minnows  in  the  brook,  is  well  acquainted 
with  this  merry  swimmer  in  his  shining  black 
jacket.  Retiring  in  the  autumn,  and  reposing  all  the 
winter  in  the  mud  at  the  bottom  of  the  pond,  it 
awakens  in  the  spring,  rises  to  the  surface,  and  com- 
mences its  summer  sports.J  They  associate  in  small 

*  J.  R.  t  Intr.,  vol.  ii,  p.  4. 

$  We  have  seen  them  throughout  the  severe  winter  of  1 829- 
30,  sporting  on  the  unfrozen  springs  at  Lee,  in  Kent.  J.  R. 


MOTIONS    OF    INSECTS.  369 

parties  of  ten  or  a  dozen,  near  the  bank,  where  some 
little  projection  forms  a  bay,  or  renders  the  water 
particularly  tranquil;  and  here  they  will  circle  round 
each  other  without  contention,  each  in  his  sphere, 
and  with  no  apparent  object,  from  morning  until 
night,  with  great  sprightliness  and  animation;  and  so 
lightly  do  they  move  on  the  fluid,  as  to  form  only 
some  faint  and  transient  circles  on  its  surface.  Very 
fond  of  society,  we  seldom  see  them  alone,  or,  if 
parted  by  accident,  they  soon  rejoin  their  busy  com- 
panions. One  pool  commonly  affords  space  for  the 
amusement  of  several  parties;  yet  they  do  not  unite 
or  contend,  but  perform  their  cheerful  circlings  in 
separate  family  associations.  If  we  interfere  with 
their  merriment  they  seem  greatly  alarmed,  disperse, 
or  dive  to  the  bottom,  where  their  fears  shortly  sub- 
side, as  we  soon  again  see  our  little  merry  friends 
gamboling  as  before.  This  plain,  tiny,  gliding 
water-flea  seems  a  very  unlikely  creature  to  arrest 
our  young  attentions;  but  the  boy  with  his  angle  has 
not  often  much  to  engage  his  notice,  and  the  social 
active  parties  of  this  nimble  swimmer,  presenting 
themselves  at  these  periods  of  vacancy,  become  in- 
sensibly familiar  to  his  sight,  and  by  many  of  us  are 
not  observed  in  after-life  without  recalling  former 
hours,  scenes  of,  perhaps,  less  anxious  days:  for 
trifles  like  these,  by  reason  of  some  association,  are 
often  remembered,  when  things  of  greater  moment 
pass  off  and  leave  no  trace  upon  the  mind.  '* 

*  The  gyrinus,'  say  Kirby  and  Spence,  *  seems 
the  merriest  and  most  agile  of  all  the  inhabitants  of 
the  waves.  Wonderful  is  the  velocity  with  which 
they  turn  round  and  round,  as  it  were  pursuing  each 
other  in  incessant  circles,  sometimes  moving  in 
oblique,  and  indeed  in  every  other  direction.  Now 
and  then  they  repose  on  the  surface  as  if  fatigued 

*  Journal  of  a  Naturalist,  p.  307^ 


370  INSECT  TRANSFORMATIONS. 

with  their  dances,  and  desirous  of  enjoying  the  full 
effect  of  the  sunbeam:  if  you  approach,  they  are 
instantaneously  in  motion  again.  Attempt  to  entrap 
them  with  your  net,  and  they  are  under  the  water  and 
dispersed  in  a  moment.  When  the  danger  ceases, 
they  re-appear  and  resume  their  vagaries.  Covered 
with  lucid  armour,  when  the  sun  shines  they  look  like 
little  dancing  masses  of  silver  and  brilliant  pearl.* 

The  gyrations  of  the  whirlwig  are  equalled  in 
rapidity  by  its  diving,  when  its  sports  are  intruded 
upon  by  our  approach.  Its  great  quickness  of  sight, 
indeed,  is  quite  surprising;  and  is  to  be  accounted  for 
by  one  of  the  most  striking  instances  of  providential 
contrivance  with  which  we  are  acquainted.  Land 
animals  see  indifferently  under  water,  and  aquatic 
animals  imperfectly  in  air;  and  an  animal  with  an 
eye  equally  fitted  for  seeing  in  water  and  in  air, 
can,  on  account  of  the  great  difference  of  the  me- 
diums, possess  but  imperfect  vision  in  either.  The 
little  whirlwig,  to  obviate  this  difficulty,  is  furnished 
with  two  sets  of  eyes,  one  pair  being  placed  on  the 
upper  part  of  the  forehead  for  seeing  in  air,  and 
another  pair  on  the  under  part  of  the  forehead,  ex- 
actly under  the  first,  and  separated  from  them  by  a 
thin  membrane,  for  seeing  in  water.  As  it  swims 
half  submerged,  the  latter  pair  of  eyes  must  be 
very  useful  in  warning  .the  insect  of  approaching 
danger,  from  fishes  or  rapacious  larvae  below,  while 
the  former  watch  with  equal  keenness  the  ap- 
proach of  enemies  above.  The  hind  feet  are  no  less 
admirably  formed  for  swimming,  being  broad,  thin 
and  elastic;  while  the  fore  feet  are  constructed  to 
answer  the  purpose  of  hands  for  the  seizing  of  prey. 
The  little  animal  is,  besides  all  these  wonderful 
organs,  furnished  with  a  pair  of  ample  wings  for 
transporting  itself,  should  the  water  of  its  native 

*  Jntr.  vol.  ii,  p.  372, 


MOTIONS  OF  INSECTS.  371 

pool  chance  to   dry  up  in  summer,  and  force  it  to 
emigrate. 

The  sporting  of  butterflies  in  pairs,  trios,  or  more, 
has  been  looked,  upon  by  some  as  pugnacious  skir- 
mishing. *  A  few  of  our  lepidopterous  creatures,' 
says  Mr  Knapp,  '  especially  the  common  white 
butterflies  of  our  gardens,  are  contentious  animals, 
and  drive  away  a  rival  from  their  haunts.  We  see 
them  progressively  ascending  into  the  air,  in  ardent 
unheeding  contest;  and  thus  they  are  observed,  cap- 
tured, and  consumed  in  a  moment  by  some  watchful 
bird;  but  we  have  few  more  jealous  and  pugnacious 
than  the  little  elegant  blue  argus  butterfly  (Polyom- 
matus  Jllexis,  STEPHENS,)  noted  and  admired  by  all. 
When  fully  animated  it  will  not  suffer  any  of  its 
tribe  to  cross  its  path,  or  approach  the  flower  on 
which  it  sits,  with  impunity;  even  the  large  admirable 
(  Vanessa  atalanta^)  at  these  times,  it  will  assail  and 
drive  away.  There  is  another  small  butterfly,  the 
copper  (Lyccena  Phlceas,  FABR.,)  however,  as  hand- 
some and,  perhaps,  still  more  quarrelsome,  frequent- 
ing too  the  same  station  and  flowers;  and  a  constant 
warfare  exists  between  them.  We  shall  see  these 
diminutive  creatures,  whenever  they  come  near  each 
other,  dart  into  action,  and  continue  buffeting  one 
another  about  till  one  retires  from  the  contest;  when 
the  victor  returns  in  triumph  to  the  station  he  had 
left.  Should  the  enemy  again  advance,  the  combat 
is  renewed;  but  should  a  cloud  obscure  the  sun,  or 
a  breeze  chill  the  air,  their  ardour  becomes  abated 
and  contention  ceases.  The  copper  butterfly  enjoys 
a  combat  even  with  its  kindred.  Two  of  them  are 
seldom  disturbed,  when  basking  on  a  knot  of  asters 
in  September,  without  mutual  strife  ensuing.  Being 
less  affected  by  cold  and  moisture  than  the  argus, 
they  remain  with  us  longer,  and  these  contentions 
are  protracted  till  late  in  the  autumn.  The  pugna- 
cious disposition  of  the  argus  butterfly  soon  deprives 


372  INSECT    TRANSFORMATIONS. 

it  of  much  of  its  beauty;  and,  unless  captured  soon 
after  its  birth,  we  find  the  margins  of  its  wings  torn 
and  jagged,  the  elegant  blue  plumage  rubbed  from  the 
wings,  and  the  creature  become  dark  and  shabby.'* 

We  are  of  opinion,  on  the  other  hand,  that  these 
butterfly  skirmishings  are  not  prompted  by  testiness 
nor  jealousy,  but  by  the  spirit  of  gaiety  and  frolic  — 
the  buoyant  feelings  arising  from  the  air  expanded 
in  their  wings ,  and  bodies  by  the  warm  sunshine, 
causing  the  living  principle  to  increase  even  to  exu- 
berance. Were  these,  indeed,  actual  combats  among 
the  males,  like  those  which  take  place  among  game- 
cocks or  ruffs  (Tringa  pugnax,  LINN.,)  nature 
would  probably  have  furnished  them  with  weapons 
suited  to  such  warfare.  But  butterflies  have  neither 
spurs,  claws,  nor  sharp  bills,  wherewith  to  assail  an 
enemy;  and  though  they  might  flap  one  another  with 
their  wings,  till  their  tiny  feathers  flew  about  like  a 
snow-shower,  yet  we  never  have  observed  them  do 
so,  as  Mr  Knapp's  description  seems  to  imply.  On 
the  contrary,  they  appear  actually  to  take  care  that 
such  an  accident  should  not  occur  while  they  frisk 
about  one  another,  rising,  falling,  and  performing 
zig-zag  pirouettes  in  the  air,  as  we  see  kittens  or 
puppies  do  on  the  ground,  in  their  more  clumsy  but 
no  less  frolicsome  gambols.  Did  these  skirmishes, 
besides,  originate  in  rivalry  or  jealousy,  we  should 
always  see  the  butterflies  combating  in  couples,  for  we 
never  see  two  or  three  game-cocks  set  upon  an  indi- 
vidual; but  it  is  by  no  means  uncommon  to  see  three 
and  we  have  qbserved  as  many  as  five  butterflies,  all 
equally  engaged  in  these  supposed  battles,  and  each 
bouncing  and  popping  indiscriminately  at  the  others 
without  ever  coming  to  blows.  It  seldom  happens 
that  they  actually  touch  one  another,  however  long 
they  may  be  at  play,  —  a  circumstance  which  of  itself 
is  sufficient  to  prove  our  position. 

*  Journal  of  a  Naturalist,  p.  277. 


MOTIONS    OF    INSECTS.  373 

A  more  extraordinary  display  of  insect  dancing, 
and  which  in  some  instances  seems  better  entitled  to 
the  name  of  a  ball,  than  our  own  dancing  parties, 
occurs  amongst  the  day-flies  (Ephemeridce) ,  whose 
short-lived  existence  renders  it  necessary  for  them  to 
make  the  most  of  the  few  hours  at  their  disposal. 
The  narrative  of  the  observations  made  by  Reaumur 
upon  this  subject  is  too  interesting  to  admit  of  much 
abridgment.  It  is  not  a  little  singular,  he  remarks, 
that  moths,  which  fly  only  in  the  night,  and  shun  the 
day,  should  be  precisely  those  that  come  to  seek  the 
light  in  our  apartments  ;  but  it  is  still  more  wonderful 
that  the  ephemerae  —  which,  appearing  after  sun-set 
and  dying  before  sun-rise,  are  destined  never  to 
behold  the  dawn  of  day,  —  should  have  so  strong  an 
inclination  for  any  luminous  object. 

It  is  usually  about  the  middle  of  August  that 
the  ephemerae  of  the  Seine  and  Marne  are  ex- 
pected by  the  fishermen,  and  when  their  season  is 
come  they  talk  of  the  manna  beginning  to  appear, 
calling  the  insects  by  this  term  on  account  of  the 
quantity  of  food  for  the  fish,  which  falls  as  the  manna 
is  recorded  to  have  done  in  the  desert.  On  the 
19th  of  August,  Reaumur,  having  received  notice 
that  the  flies  had  begun  to  appear,  and  that  millions 
of  them  were  coming  out  of  the  water,  got  into  his 
boat  about  three  hours  before  sunset ;  but  after  stay- 
ing in  the  boat  till  eight  o'clock  without  seeing  any, 
he  resolved,  as  a  storm  was  foreboded,  to  return. 
He  had  previously  detached  from  the  banks  of  the 
river  several  masses  of  earth  filled  with  pupae,  which 
he  put  into  a  large  tub  full  of  water.  His  servants, 
who  were  carrying  the  tub  home,  had  scarcely  set  it 
upon  one  of  the  steps  of  the  stairs  leading  from  his 
garden  to  the  Marne,  when  he  heard  them  exclaim, 
'  What  a  prodigious  number  of  ephemeras  are  here  !' 
He  immediately  seized  one  of  the  torches  and  ran  to 

VOL.  vi.  32 


374  INSECT    TRANSFORMATIONS. 

the  tub,  where  he  found  every  piece  of  earth  above 
the  surface  of  the  water  swarming  with  the  flies, 
some  just  beginning  to  quit  their  old  skin,  others 
preparing  to  fly,  and  others  already  on  the  wing, 
while  every  where  under  water  they  were  seen  in  a 
greater  or  less  degree  of  forwardness.  The  threaten- 
ed storm  of  rain  and  lightening  at  length  coming  on, 
he  was  compelled  to  leave  the  interesting  scene  ;  but, 
to  prevent  the  escape  of  the  insects,  he  had  the  tub 
covered  with  a  cloth.  The  violence  of  the  rain  ceas- 
ed in  about  half  an  hour,  when  he  returned  to  the 
garden,  and  as  soon  as  the  cloth  was  removed  from 
the  tub  he  perceived  that  the  number  of  the  flies  was 
prodigiously  augmented,  and  continued  to  increase  for 
some  time  as  he  sto®d  watching  them.  Many  flew 
away,  and  many  more  were  drowned,  but  the  number 
which  had  already  undergone  their  transformation 
from  the  earth  in  the  tub  would  have  been  sufficient 
to  fill  it,  exclusively  of  crowds  of  others  which  the 
light  had  attracted  from  a  distance.  He  again  spread 
the  cloth  over  the  tub,  and  the  light  was  held  above 
it  :  immediately  the  cloth  was  almost  concealed  by 
the  vast  multitudes  which  alighted  upon  it,  and  they 
might  have  been  taken  by  handfulls  from  the  candle- 
stick. What  he  had  observed,  however,  at  the  tub, 
was  nothing  to  the  scene  now  exhibited  on  the  banks 
of  the  river,  to  which  he  was  again  attracted  by  the 
exclamations  of  his  gardener. 

c  The  countless  numbers,'  he  says,  '  of  ephe- 
merae which  swarmed  over  the  water  can  neither  be 
conceived  nor  expressed.  When  snow  falls  thickest 
and  in  the  largest  flakes,  the  air  is  never  so  com- 
pletely full  of  them  as  that  which  we  witnessed  filled 
with  ephemerae.  I  had  scarcely  remained  a  few 
minutes  in  one  place,  when  the  step  on  which  I  stood 
was  covered  in  every  part  with  their  bodies,  from  two 
to  four  inches  in  depth.  Near  the  lowest  step,  a 


MOTIONS    OF    INSECTS.  375 

surface  of  water,  of  five  or  six  feet  dimensions  every 
way,  was  entirely  covered  with  a  thick  layer  of  them, 
and  those  which  the  stream  swept  away  were  more 
than  replaced  by  the  multitudes  that  were  continually 
falling.  I  was  repeatedly  compelled  to  abandon  my 
station,  from  not  being  able  to  bear  the  shower  of 
insects,  which,  not  falling  perpendicularly  like  rain, 
struck  me  incessantly  and  in  a  manner  extremely 
uncomfortable,  pelting  against  every  part  of  my  face, 
and  filling  my  eyes,  nose,  and  mouth  almost  to  suffo- 
cation. On  this  occasion  it  was  no  pleasant  post  to 
hold  the  light,  for  our  torch-bearer  had  his  clothes 
covered  with  the  insects  in  a  few  moments,  which 
rushed  in  from  all  quarters  to  overwhelm  him. 

'  The  light  of  the  torch  gave  origin  to  a  spectacle 
which  enchanted  every  one  who  beheld  it,  and  alto- 
gether different  from  a  meteorological  shower  ;  even 
the  most  stupid  and  unobserving  of  my  domestics  were 
never  satisfied  with  gazing  at  it.  No  armillary  sphere 
was  ever  formed  of  so  many  circular  zones  in  every 
possible  direction,  having  the  light  for  their  common 
centre.  Their  number  seemed  to  be  infinite,  crossing 
each  other  in  all  directions,  and  in  every  imaginable 
degree  and  inclination  —  all  of  which  were  more  or 
less  oblique.  Each  of  these  zones  was  composed  of 
an  unbroken  string  of  ephemera?,  which  followed  each 
other  close  in  the  same  line  as  if  they  had  been  tied 
together  head  and  tail,  resembling  a  piece  of  silver 
ribbon  deeply  indented  on  its  edges,  and  consisting 
of  equal  triangles  placed  end  to  end  —  so  that  the 
angles  of  those  that  followed  were  supported  by  the 
base  of  those  which  preceded,  the  whole  moving 
round  with  incredible  velocity.  This  spectacle  was 
caused  by  the  wings  of  the  insects,  which  alone  could 
be  distinguished.  Each  of  these  flies,  after  having 
described  one  or  two  orbits,  fell  to  the  earth,  or  into 


376  INSECT    TRANSFORMATIONS. 

the  water,  though  not  in  consequence  of  having  been 
burned.'* 

It  is  conjectured  by  Kirby  and  Spence,  that 
Reaumur,  though  he  was  unquestionably  a  most 
accurate  observer,  may  have  mistaken  the  rapid 
movements  of  single  flies,  and  the  deception  of  vision 
thence  arising,  for  a  numerous  troop,  following  one 
another  in  zoned  circular  lines,  —  a  mistake  which 
they  were  once  upon  the  point  of  committing  when 
observing  the  dances  of  certain  small  flies  which 
moved  in  spirals;  closer  observation,  however,  proved 
that  what  appeared  to  be  a  continuous  line  of  flies, 
was  produced  by  the  rapid  motion  of  an  individual. 
Be  this  as  it  may,  it  will  not  alter  the  singularity  of 
the  spectacle.  Some  of  our  British  ephemera?  begin 
their  dances  with  the  dawn,  instead  of  waiting  till 
sun-set,  —  rising  and  falling  continually  over  the 
meadows  in  May,  sometimes  beating  the  air  rapidly 
with  their  wings,  and  sometimes  skimming  about  like 
hawks.  |  Those  again  which  we  observed  in  August, 
rising  from  the  Rhine,  did  not  dance  at  all,  but  flew 
in  a  heavy,  unsteady,  and  lumbering  manner  above 
the  current  of  the  river.  J 

In  speaking  of  what  appear  to  be  the  sports  of 
insects,  we  cannot  omit  taking  notice  of  the  very 
singular  proceedings  of  some  species  of  ants,  which, 
at  the  intervals  of  busy  industry,  amuse  themselves 
with  something  apparently  analogous  to  our  wrest- 
ling and  racing  matches.  Bonnet  says,  he  observed 
a  small  species  of  ants,  which  employed  themselves 
in  carrying  each  other  on  their  backs,  the  rider  hold- 
ing with  his  mandibles  the  neck  of  his  bearer,  and 
embracing  it  closely  with  his  legs,§  the  position 

*  Reaumur,  Mem.  vol.  vi,  p.  485. 

t  Kirby  and  Spence,  vol.  ii,  p.  373.  t  J.  R. 

§  Bonnet,  CEuvres,  vol.  ii,  p.  407. 


MOTIONS   OF    INSECTS.  377 

which  the  renowned  John  Gilpin  may  have  some- 
times been  disposed  to  assume  in  his  famous  race 
through  Edmonton.  But  though  the  very  palpable 
mistakes  committed  by  Bonnet  respecting  these  very 
ants*  may,  perhaps,  tend  to  invalidate  his  authority 
with  respect  to  their  riding,  we  have  the  undoubted 
testimony  of  both  Gould  and  Huber  for  their  wrest- 
lings. c  You  may  frequently,'  says  Gould,  '  per- 
ceive one  of  these  ants  (Formica  rufa,  LATR.)  run 
to  and  fro  with  a  fellow-labourer  in  his  forceps  of 
the  same  species  and  colony.'  Mr  Gould  observed, 
that,  after  being  carried  for  some  time,  it  was  let  go 
in  a  friendly  manner  and  received  no  personal  injury. 
This  amusement  is  often  repeated,  particularly  among 
the  hill  ants,  who  are  very  fond  of  this  sportive 
exercise,  "f* 

It  was  amongst  the  same  species,  that  Huber  ob- 
served similar  proceedings,  which  he  has  described  with 
his  usual  minuteness  and  accuracy.  c  I  approached,' 
he  says,  '  one  day  to  the  formicary  of  wood  ants, 
exposed  to  the  sun  and  sheltered  from  the  north 
The  ants  were  heaped  upon  one  another  in  great 
numbers,  and  appeared  to  enjoy  the  temperature  on 
the  surface  of  the  nest.  None  of  them  were  at  work, 
and  the  immense  multitude  of  insects  presented  the 
appearance  of  a  liquid  in  the  state  of  ebullition,  upon 
which  the  eye  could  scarcely  be  fixed  without  diffi- 
culty ;  but  when  1  examined  the  conduct  of  each 
ant,  I  saw  them  approach  one  another,  moving  their 
antennaB  with  astonishing  rapidity,  while  they  patted 
with  a  slight  movement  the  cheeks  of  other  ants. 
After  these  preliminary  gestures  which  resembled 
caressing,  they  were  observed  to  raise  themselves 
upright  on  their  hind  legs  by  pairs,  struggle  together, 
seize  each  other  by  a  mandible,  foot,  or  antenna,  and 

*  Huber  on  Ants,  pref.    and  pp.  211  and  233. 
t  Gould  on  Ants,  p.  102,  &c. 
VOL.  vi.  32* 


378  INSECT    TRANSFORMATIONS. 

then  immediately  relax  their  hold  to  recommence  the 
attack.  They  fastened  upon  each  other's  shoulders, 
or  bellies,  embraced  and  overthrew  each  other,  then 
raised  themselves  by  turns,  taking  their  revenge 
without  producing  any  serious  mischief.  They  did  not 
spurt  out  their  venom  as  in  their  combats,  nor  retain 
their  opponents  with  that  obstinacy  which  we  observe 
in  their  real  quarrels.  They  presently  abandoned 
those  which  they  had  first  seized,  and  endeavoured  to 
catch  others.  I  have  seen  some  who  were  so  eager 
in  these  exercises,  that  they  pursued  several  workers 
in  succession,  and  struggled  with  them  a  few  mo- 
ments, the  skirmish  only  terminating  when  the  least 
animated,  having  overthrown  his  antagonist,  succeeded 
in  escaping  and  hiding  in  one  of  the  galleries.  In 
one  place,  two  ants  appeared  to  be  gamboling 
about  a  stalk  of  grass,  —  turning  alternately  to  avoid 
or  seize  each  other,  which  brought  to  my  recollection 
the  sport  and  pastime  of  young  dogs  when  they  rise 
on  their  hind-legs,  attempting  to  bite,  overthrow,  and 
seize  each  other,  without  once  closing  their  teeth. 
To  witness  these  facts,  it  is  necessary  to  approach  the 
ant-hills  with  much  caution,  that  the  ants  should 
have  no  idea  of  our  presence  ;  if  they  had,  they 
would  cease  at  the  moment  their  plays  or  their  occu- 
pations, would  put  themselves  in  a  posture  of  defence, 
curve  up  their  tails,  and  ejaculate  their  venom."* 

*  M.  P.  Huber  on  Ants,  p.  203, 


CHAPTER    XVI. 

Peculiar  Locomotions. 

THOSE  who  have  attended  to  the  paces  of  the  larger 
animals,  are  well  aware  of  their  almost  infinite 
variety ;  but  the  differences  between  the  heavy  tread  of 
the  elephant  or  the  waddling  roll  of  an  overgrown 
pig,  the  elegant  pace  of  a  blood-horse  or  the 
sprightly  trip  of  an  antelope,  will  bear  no  comparison 
with  the  infinite  diversities  observable  among  the 
movements  of  insects.  We  look  upon  the  long  legs 
of  the  giraffe  and  the  crane  as  inelegant  and  dispro- 
portionate, how  well  suited  soever  they  may  be  to 
their  mode  of  life  :  but  what  should  we  think  of  a 
species  of  giraffe,  with  legs  long  enough  to  enable  it 
to  overtop  the  tallest  trees,  so  as  to  browse  on  their- 
tops  as  oxen  do  on  the  grass  of  a  meadow,  while  it 
walked  at  ease  through  woods  and  forests ;  or  of  a 
wren  or  sparrow  with  legs  as  long  as  the  hop-poles 
among  which  it  prowled  to  prey  upon  aphides  and 
lady-birds.  But  animals  of  such  descriptions,  wildly 
imaginary  as  they  must  be  confessed  to  be,  may  be 
readily  matched  in  the  insect  world.  The  pendulum 
crane  fly  (Tipula  motitatrix),  formerly  mentioned, 
as  well  as  the  shepherd  spider  (Phalangium 
opilio},  described  in  the  same  place,  are  remarkable 
examples  of  this  ;  and  we  have  still  more  striking 
instances  in  the  large  clouded- winged  crane  fly 
(Tipula  gigantea,  MEIGEN),  popularly  termed  father 
longlegs,  or  jenny-spinner,  their  stilted  legs  enabling 
these  insects  to  overtop  the  grass  as  they  walk  in  the 
meadows,  in  the  same  way  as  our  imaginary  giraffe 


380  INSECT    TRANSFORMATIONS. 

would  overtop  the  trees  in  a  forest.  We  have  been 
more  struck  with  instances  of  this  in  some  of  the 
bug  tribe,  because  here  it  was  least  to  have  been 
expected.  In  our  earlier  entomological  researches, 
we  frequently  noticed,  upon  a  white-washed  wall,  a 
very  strange  looking  insect,  if  insect  it  might  be 
called,  moving  about  in  the  most  awkward  manner 
imaginable.  It  looked,  however,  more  like  a  slip  of 
gray  tree  bark,  not  half  the  breadth  of  a  wheat-straw, 
that  had  been  accidentally  caught  on  some  straggling 
films  of  spider's  web,  which  allowed  it  to  oscillate 
irregularly  in  the  air,  than  a  real  living  creature,  —  for 
the  long  gossamer  legs  did  not,  to  the  unassisted  eye, 
appear  to  move  at  all,  and  the  slender  awkward 
body  progressed  by  interrupted  jerks  (if  such 
slow  motions  may  be  so  termed),  resembling  the 
movement  of  the  minute-hand  of  a  clock.  The 
glass,  however,  showed  that  the  body  was  covered  by 
the  folds  of  four  membranous  wings,  prettily  mottled, 
which  lay  in  a  hollow  groove  on  the  back,  while  the 
long  slender  legs  were  elegantly  ringed  with  white 
It  was,  in  short,  one  of  the  numerous  family  of  plant- 
bugs  (Neides  elegans  ?  CURTIS)  which  had  strayed 
from  the  adjacent  garden  to  the  wall.  Another 
occurred  in  the  same  place  somewhat  similar,  but 
considerably  smaller,  and  stalked  along  with  equally 
awkward  jerks,  upon  only  its  four  hind-legs,  while  it 
kept  its  two  fore-legs,  which  were  greatly  shorter, 
folded  up  under  its  belly,  in  readiness,  probably,  to 
seize  on  the  first  luckless  mite  or  aphis  that  came  in 
its  way.*  The  latter  appears  to  be  the  wandering 
plant-bug  (Ploiaria  vagabunda,  SCOPOLI). 

Many  insects  are  capable  of  performing  a  feat 
which  no  other  animal  could  accomplish  without  the 
aid  of  the  water-shoes  lately  invented  —  we  allude  to 
walking  on  the  water,  as  distinct  from  swimming, 

*  J.  R. 


PECULIAR    MOTIONS  OF    INSECTS. 


381 


a,  Ploiaria  vagabunda,  magnified.    6,  Neides  elegans^  magnified, 

which  most,  if  not  all  animals,  save  man,  can  do 
without  instruction.  The  whirlwig  beetle  (Gyrinus 
natator)  can  scarcely  be  said  either  to  walk,  run,  or 
swim,  —  for,  as  we  have  taken  some  pains  to  ascertain, 
it  appears  not  to  keep  its  *  oary  feet'  plunged  in 
the  water  as  it  flits  about,  but  strikes  smartly  out, 
and  suddenly  folds  them  flat  under  its  belly;  on  the 
same  principle  as  a  waterman  on  the  Thames  may 
be  seen  to  give  two  or  three  quick  pulls  with  his  oars, 
to  put  way,  as  he  calls  it,  upon  his  wherry,  and  then 
perking  them  up  out  of  the  water,  lets  it  skim  along 
while  he  rests  motionless.  Thus  does  the  little 
whirlwig  glide  along  the  water  as  if  by  magic,  for 
we  cannot  see  its  feet  moving  on  account  of  the 
border  of  the  wing  cases  (elytra)  which  overlap 
them ;  no  more  than  we  can  discern  the  feet  of  a  swan, 
from  their  dark  colour,  resembling  that  of  the  water, 
even  when  she  skims  about  at  a  small  distance  from 
the  shore.* 

Most  people  must  have  been  amused  by  observing 
the  groups  of  water  insects  which  seem  to  delight  in 

*  J.R. 


382  INSECT    TRANSFORMATIONS. 

swimming  against  small  streams,  and  apparently  more 
for  the  purpose  of  maintaining  their  place  than  of 
making  further  progress  upwards.  The  most  com- 
mon of  these  are  two  aquatic  bugs  of  different  gene- 
ra—  the  one  (Gerris  locustris,  LATR.)  with  a  long 
blackish  body  and  legs,  and  white  belly,  though  more 
clumsy  in  form  than  the  water  measurer  (Hydrometra 
stagnorum)  formerly  mentioned;  and  the  other  (Ve- 
lia  currens,  LATR.),  with  short  body  and  feet, 
black,  with  a  red  line  running  along  each  side.  We 
have  been  still  more  amused  with  a  dark  greenish 
gray  spider  (Lycosa  Saccata,  LATR.),  which,  when 
we  approach  near  its  haunts  on  the  margin  of  a 
stream,  does  not  take  shelter  in  the  grass,  nor  in  the 
holes  of  the  bank,  as  most  of  its  kindred  would  do, 
but  trips  away  over  the  water,  where  it  appears  to 
know  instinctively  that  we  cannot  so  easily  pursue  it. 
This  is  not,  however,  the  diving  water  spider  (Jlr- 
gyroneta  aquatica),  for  though  it  can  dive  and  remain 
under  water,  it  does  not  seem  to  relish  this,  except 
when  driven  to  the  measure.* 


6,  Hydrometra  stag-riorum,    c  d,  Hydrachna   Geographica,  Latr., 
front  and  back  view,  both  magnified,    e,  Velia  rivulorum,  Latr. 

*  J.  R. 


PECULIAR    MOTIONS    OF    INSECTS.  383 

Some  of  these  water  insects  have  such  slender  feet, 
that  we  can  only  explain  their  not  sinking  in  the  wa- 
ter on  the  same  principle  as  that  of  a  small  needle 
floating  when  very  dry  and  laid  exactly  level.  Others 
again  have  their  feet  fringed  with  fine  hairs  which 
buoy  them  up ;  while  the  tipulidan  gnats  (  Chironomi) 
and  other  flies,  are,  perhaps,  aided  by  their  wings  in 
keeping  them  afloat;  for  we  have  observed  several 
aquatic  flies  skimming  on  the  surface  of  the  water, 
apparently  half  running,  half  flying.  Linnasus  saw 
one  of  these  little  tipulae,  of  a  black  colour,  perform- 
ing gyrations  on  the  water  similar  to  those  of  the 
whirlwig  (Gyrinus):  others  use  their  wings  as  the 
swan  does,  by  way  of  a  sail. 

Other  insects  walk  both  through  the  water,  and  at 
its  bottom,  in  a  similar  manner  to  walking  on  land, 
and  not  by  striking  with  their  feet,  as  is  done  in 
swimming.  It  is  in  this  manner  that  the  minute 
pretty  water- mite  (Hydrachna  geographica,  MUL- 
LER),  may  be  seen  in  every  ditch  and  pond  around 
London,  pacing  along,  often  in  company  with  a  still 
more  showy  one  (Limnochares  holosericea,  LATR.), 
whose  bright  scarlet  colour  renders  it  very  easily  re- 
cognised, and  may  readily  lead  a  young  naturalist  to 
suppose  that  the  scarlet  satin  mite  (Trombidiutn 
holosericeum,  LATR.),  so  frequent  on  dry  banks  in  the 
spring,  has  abandoned  the  land  for  the  water.  The 
latter,  however,  is  much  larger. 

The  amphibious  nature  of  those  winged  beetles 
which  can  walk  at  the  bottom  of  water,  is  matched, 
if  not  out-rivalled,  by  the  water-ouzel  (Cinclus 
aquations ,  BECHSTEIN),  which  we  have  repeatedly  seen 
walk  deliberately  under  water,  and  continue  its  pace 
for  many  yards,  as  if  it  had  been  on  land.*  As  this 

*  J.  R. 


384  INSECT     TRANSFORMATIONS. 

little  bird  lives  on  water  insects  and  the  fry  of  fish, 
its  amphibious  powers  are  indispensable. 

Some  of  these  aquatic  insects,  such  as  the  whirlwig, 
are  so  highly  polished,  that  the  water  will  not  adhere 
to  their  bodies;  while  others  (Hydrophili,  &c,)  are 
covered  below  with  a  thick  coating  of  silky  hair,  which 
repels  the  water  and  usually  surrounds  them  with  a 
globule  of  air  that  shines  under  water  like  quicksilver. 
The  spider  mentioned  above  is  similarly  furnished  with 
downy  hair  for  the  same  purpose. 

In  walking,  insects  exhibit  endless  peculiarities. 
The  hunting  spiders,  and  many  of  the  midges  (Psy- 
chodce,  LATR.),  instead  of  walking  straightforwards, 
most  usually  walk  obliquely,  and  often  at  right-angles 
to  the  line  of  their  own  bodies;  while  most  insects 
can,  when  it  is  necessary,  walk  directly  backwards 
with  almost  as  much  facility  as  forwards.  When 
the  centipedes  (Scolopendridce,  LEACH)  walk  back- 
wards, they  only  use  their  four  hind-legs,  and  these, 
when  they  walk  in  the  usual  way,  are  not  employed, 
but  dragged  after  them  like  the  locked  wheel  of  a  mail- 
coach  in  driving  down  a  steep  hill.  It  was  first 
observed,  we  believe,  by  Kirby,  that  a  millepede 
common  under  stones,  the  bark  of  trees,  and  the 
hollow  stems  of  decaying  plants,  and  pro vinci ally 
called  maggy-manyfeet  (Jttt*a  terrcshis),  performs 
its  serpent-like  motion  by  extending  alternate  por- 
tions of  its  numerous  legs  beyond  the  line  of  the 
body,  while  those  in  the  intervals  preserve  a  vertical 
direction.  So  long,  then,  as  it  keeps  moving,  little 
bunches  of  the  legs  are  alternately  in  and  out  from 
one  end  to  the  other  of  its  long  body,  the  undulating 
line  of  motion  successively  beginning  at  the  head  and 
passing  off  at  the  tail.*  We  may  add,  that  the  form 
and  structure  of  this  insect  are  admirably  adapted 

*  Intr.,  vol.  ii,  p.  309. 


PECULIAR    MOTIONS   OF    INSECTS.  385 

to  its  mode  of  life,  it  being  long  and  of  small  dia- 
meter, to  enable  it  to  thread  its  way  through  narrow 
holes,  while  its  covering  is  highly  polished  to  facili- 
tate its  passage,  and  so  hard  as  to  prevent  it  being 
lacerated  by  any  splinter  of  wood  which  it  might 
chance  to  encounter,  while  it  is  at  the  same  time  so 
flexible,  that  it  can  coil  itself  up  into  a  circle  of  very 
small  diameter.  The  hardness  and  the  flexibility, 
though  apparently  incompatible,  are  produced  by  a 
similar  contrivance  to  that  of  the  spine  in  man  —  the 
whole  body  of  the  julus  being  composed  of  small 
hard  rings  united  by  flexible  joints.* 

Instances  have  occurred  in  which  a  sheep  or  a 
cow  has  come  into  the  worl^  with  legs  upon  its  back  : 
this,  of  course,  is  a  monstrosity  out  of  the  usual  course 
of  nature;  but  in  a  very  singular  insect,  the  bat- 
louse  (Nycteribia  Hermanni,  LEACH),  the  legs 
appear  to  have  their  usual  place  on  the  back.  '  It 
transports  itself,'  says  Colonel  Montagu,  c  with 
such  celerity,  from  one  part  of  the  animal  it  inhabits 
to  the  opposite  and  most  distant,  although  obstructed 
by  the  extreme  thickness  of  the  fur,  that  it  is  not 
readily  taken.'  —  c  When  two  or  three  were  put  into 
a  small  phial,  their  agility  appeared  inconceivably 
great ;  for,  as  their  feet  are  incapable  of  fixing  upon 
so  smooth  a  body,  their  whole  exertion  was  employed 
in  laying  hold  of  each  other;  and  in  this  most  curious 
struggle,  they  appeared  actually  flying  in  circles: 
and  when  the  bottle  was  reclined,  they  would  fre- 
quently pass  from  one  end  to  the  other  with  astonish- 
ing velocity,  accompanied  by  the  same  gyrations  ;  if 
by  accident  they  escaped  each  other,  they  very  soon 
became  motionless  ;  and  as  quickly  were  the  whole 
put  in  motion  again  by  the  least  touch  of  the  bottle 
or  the  movement  of  an  individual. 'f 

Many  of  the  beetles  run  with  great  velocity,  and 

*  J.  R.  t  Linn.  Trans,  vol.  xi,  p.  13. 

VOL.  vi.  33 


386 


INSECT    TRANSFORMATIONS. 


dart  off  into  holes  and  corners  so  suddenly,  as  often 
to  escape  the  quickest  movements  of  an  insect 
hunter.  It  is  remarkable,  however,  that  those  swift- 
footed  insects  seldom  run  far  without  making  a  full 
pause  to  reconnoitre  their  position,  as  a  deer  may  be 
seen  to  arch  his  neck  from  behind  a  tree  to  examine 
a  stranger,  and,  after  tripping  off  to  some  distance, 
turn  round  again  to  take  another  peep  at  the  intruder. 
The  same  habit  is  observable  among  spiders,  partic- 
ularly the  hunters,  and  those  which  run  about 
meadows  and  the  margins  of  water  (Lycosa  saccata, 
&c.)  Some  of  the  mites  are  still  more  rapid  in  their 
movements,  and  we  have  often  admired  a  very  com- 
mon one  (Gammasus  Baccarum,  FABR.)  which  fre- 
quents strawberry-beds  in  gardens,  and,  as  Kirby 
and  Spence  justly  say,  appears  rather  to  glide  or  fly 
than  to  use  its  legs.*  Its  minuteness  adds  to  the 

o 


A,  Julus  tcrrestris.    i,  the  same  coiled    up.    c, 
scarabaeus  vulgaris).     d,  Nycteribia  Hei 

*  Intr.  vol.  ii,  p.  311. 


oil  beetle  (P> . 
rwuznni. 


PECULIAR    MOTIONS    OF    INSECTS.  3&7 

surprise  produced  by  its  movements,  for  it  is  little 
larger  than  a  grain  of  sand,  of  a  pale  reddish  colour, 
with  two  black  dots  on  the  back;-— and  though  the 
clods  of  garden-mould  are  mountains  in  comparison 
to  its  size,  it  gallops  over  them  at  a  thousand  times 
greater  proportional  speed  than  the  swiftest  race- 
horse.* 

As  a  contrast  to  the  quick  moving  insects  just 
mentioned,  we  may  turn  for  a  moment  to  those  which 
move  very  slowly.  The  hunting  spiders,  though  they 
can  dart  with  the  rapidity  of  lightning  upon  their 
prey,  yet  take  care  to  approach  a  victim  with  such 
extraordinary  caution,  that  the  shadow  upon  a  sun-dial 
advances  not  more  imperceptibly,  t  Some  of  the 
beetles  again  move  very  slowly,  particularly  the  one 
popularly  called  the  oil-beetle  (Proscarabceus  vul- 
garis,  STEPHENS),  on  account  of  the  oily -looking 
fluid  which  oozes  out  from  it  when  seized  or  alarmed. 
The  unwieldy  bulk  of  this  animal  makes  it  almost 
painful  to  look  at  the  efforts  it  apparently  has  to 
make  as  it  lumbers  along.  It  always  reminds  us 
of  those  bees  which,  during  autumn,  may  often  be 
seen  crawling  lifelessly  upon  flowers,  as  if  so  over- 
gorged  with  the  honey  which  they  had  extracted,  that 
they  are  unfit  to  fly.  How  the  oil-beetle  becomes 
so  fat,  it  is  not  easy  to  say,  when  we  consider  that  it 
feeds  upon  plants,  and  is  seen  very  early  in  spring. 
After  the  severe  winter  of  1 829-30,  we  found  several, 
in  the  beginning  of  March,  feeding  on  the  bulbous- 
rooted  buttercup  (Ranunculus  bulbosus],  at  Charl- 
ton,  in  Kent,  and  as  plump  as  if  there  had  not  been 
a  day's  frost  during  the  winter. 

Another  very  common  insect,  popularly  called  the 
bloody-nosed  beetle  ( Timarcha  tenebricosa,  ME- 
GERLE),  from  its  ejecting  a  red  fluid  from  its  mouth 
when  caught,  is  one  of  the  very  slow  walkers;  but 

*  J.  R.  t  Insect  Architecture,  p.  355. 


388  INSECT    TRANSFORMATIONS. 

it  is  furnished  with  feet  most  admirably  contrived  for 
taking  hold  of  the  catch  weed  (Galium  JLpamne), 
and  other  trailing  plants,  on  which  it  feeds.  This 
contrivance  consists  of  cushions,  formed  of  a  slightly 
concave  mass  of  thick  soft  hair,  which  both  adheres 
by  its  points,  and  also  produces  somewhat  of  a  va- 
cuum, which  enables  it  to  walk  as  easily  with  its  head 
perpendicularly  downwards  as  upwards. 

The  most  perfect  contrivance  of  this  kind,  however, 
occurs  in  the  domestic  fly  (Musca  domestica),  and 
its  congeners,  as  well  as  in  several  other  insects. 
Few  can  have  failed  to  remark,  that  flies  walk  with 
the  utmost  ease  along  the  ceiling  of  a  room,  and  no  less 
so  upon  a  perpendicular  looking-glass;  and  though 
this  were  turned  downwards,  the  flies  would  not  fall 
off,  but  could  maintain  their  position  undisturbed 
with  their  backs  hanging  downwards.  The  conjectures 
devised  by  naturalists,  to  account  for  this  singular 
circumstance,  previous  to  the  ascertaining  of  the 
actual  facts,  are  not  a  little  amusing.  c  Some  sup- 
pose,' says  the  Abbe  de  la  Pluche,  '  that  when  the 
fly  marches  over  any  polished  body,  on  which  neither 
her  claws  nor  her  points  can  fasten,  she  sometimes 
compresses  her  sponge  and  causes  it  to  evacuate  a 
fluid,  which  fixes  her  in  such  a  manner  as  prevents 
her  falling  without  diminishing  the  facility  of  her 
progress;  but  it  is  much  more  probable,  that  the- 
sponges  correspond  with  the  fleshy  balls  which  ac- 
company the  claws  of  dogs  and  cats,*  and  that  they 
enable  the  fly  to  proceed  with  a  softer  pace,  and  con- 
tribute to  the  preservation  of  its  claws,  whose  pointed 
extremities  would  soon  be  impaired  without  this 
prevention. 't —  c  Its  ability  to  walk  on  glass/ says 
S.  Shaw,  c  proceeds  partly  from  some  little  rugged- 
ness  thereon,  but  chiefly  from  a  tarnish,  or  dirty 

*  See  Menageries,  Lib.  of  Entertain.  Knowl.  vol.  i,  p.  173. 
t  Sped,  de  la  Nat.  vol.  i,  p.  116. 


PECULIAR    MOTIONS    OF    INSECTS.  38^ 

smoky  substance,  adhering  to  the  surface;  so  that, 
though  the  sharp  points  on  the  sponges  cannot  pene- 
trate the  surface  of  the  glass,  it  may  easily  catch  hold 
of  the  tarnish.'*  This  is  evidently  brorrowed  from 
Hook. |  But  it  is  singular  that  none  of  these  fanciers 
ever  took  the  trouble  to  ascertain  the  existence  of  either 
a  gluten  squeezed  out  by  the  fly,  or  of  the  smoky  tar- 
nish on  glass.  Even  the  shrewd  Reaumur  could  not 
give  a  satisfactory  explanation  of  the  circumstance. 

The  earliest  correct  notion  on  this  curious  subject 
was  entertained  by  Derham,  who,  upon  mentioning 
the  provision  made  for  insects  that  hang  on  smooth 
surfaces,  says,  'I  might  here  name  divers  flies  and 
other  insects,  who,  besides  their  sharp-hooked  nails, 
have  also  skinny  palms  to  their  feet  to  enable  them 
to  stick  to  glass  and  other  smooth  bodies,  by  means 
of  the  pressure  of  the  atmosphere — after  the  manner 
as  I  have  seen  boys  carry  heavy  stones  with  only  a 
wet  piece  of  leather  clapped  on  the  top  of  the  stone. 'J 
The  justly  celebrated  Mr  White,  of  Selborne,  ap- 
parently without  the  aid  of  microscopical  investiga- 
tion, adopted  Derham's  opinion,  adding  the  interest 
ing  illustration,  that  in  the  decline  of  the  year,  when 
the  flies  crowd  to  windows  and  become  sluggish  and 
torpid,  they  are  scarcely  able  to  lift  their  legs,  which 
seem  glued  to  the  glass,  where  many  actually  stick  till 
they  die ;  whereas  they  are,  during  warm  weather,  so 
brisk  and  alert  that  they  easily  overcome  the  pressure 
of  the  atmosphere.  § 

This  singular  mechanism,  however,  is  not  peculiar 
to  flies,  for  some  animals,  a  hundred  times  as  large, 
can  walk  upon  glass  by  the  same  means.  St  Pierre 

*  Nature  Displ.,  vol.  iii,  p.  98.  Lond.  1823, 

t  Micrographia,  p.  170* 

t  Physico-Theology,  vol.  ii,  p.  194,  note  (fe),  llth  ed. 

§  Nat.  Hist,  of  Selborne,  vol.  ii,  p.  274. 

VOL.  vi.  33* 


390  INSECT    TRANSFORMATIONS. 

mentions  *  a  very  small  handsome  lizard,  about  a  fin- 
ger's length,  which  climbs  along  the  walls,  and  even 
along  glass,  in  pursuit  of  flies  and  other  insects;'*  and 
Sir  Joseph  Banks  noticed  another  lizard,  named  the 
gecko  (Lacerta  Gecko,  LINN.)  which  could  walk 
against  gravity,  and  which  made  him  desirous  of  hav- 
ing the  subject  thoroughly  investigated.  On  mention- 
ing it  to  Sir  Everard  Home,  he  and  Mr  Bauer  com- 
menced a  series  of  researches,  by  which  they  proved 
incontrovertibly,  that  in  climbing  upon  glass,  and  walk- 
ing along  the  ceilings  with  the  back  downwards,  a  va- 
cuum is  produced  by  a  particular  apparatus  in  the  feet, 
sufficient  to  cause  atmospheric  pressure  upon  their  ex- 
terior surface. 

The  apparatus  in  the  feet  of  the  fly  consists  of  two 
or  three  membranous  suckers  connected  with  the  last 
joint  of  the  foot  by  a  narrow  neck,  of  a  funnel  shape, 
immediately  under  the  base  of  each  claw,  and  moveable 
in  all  directions.  These  suckers  are  convex  above  and 
hollow  below  the  edges,  being  margined  with  minute 
serratures,  and  the  hollow  portion  covered  with  down. 
In  order  to  produce  the  vacuum  and  the  pressure,  these 
membranes  are  separated  and  expanded,  and  when  the 
fly  is  about  to  lift  its  foot,  it  brings  them  together,  and 
folds  them  up  as  it  were  between  the  two  claws.  By 
means  of  a  common  microscope,  these  interesting 
movements  may  be  observed  when  a  fly  is  confined  in 
a  wine-glass. | 

It  is  a  very  remarkable  analogy,  that  many  flying 
insects,  as  well  as  many  birds,  instead  of  walking, 
leap  or  hop  along  somewhat  in  the  manner  of  a 
kangaroo  or  a  jerboa.  But  the  most  common  and 
best  known  instance  of  a  leaping  insect,  is  the  flea 
(Pulex  irritans))  whose  wings  are,  according  to 
Kirby,  obsolescent.  The  structure  of  this  annoying 

*  Voyage  to  the  Isle  of  France,  p.  73. 
t  Philosoph.  Trans,  for  1816,  p.  325. 


PECULIAR    MOTIONS    OF    INSECTS. 


Feet  of  the  blue-bottle  fly,  magnified  6400  times.  A,  a  view  of  the  un- 
der side  of  the  last  joint  of  the  toe,  with  the  two  suckers  expanded,  as 
seen  when  the  fly  is  walking  against  gravity.  B,  side  of  ditto. 


Feet  of  the  bibio  ftbriiis,  (Latr.,)  magnified  6400  times.  A,  the  under 
*3ide  of  the  last  joint  of  the  toe,  with  the  three  suckers  expanded.  B, 
side  view  of  ditto. 


INSECT    TRANSFORMATIONS. 

creature  is  well  fitted  for  its  mode  of  life — it  being  fur- 
nished with  so  tough  a  skin  that  it  is  no  easy  matter  to 
crush  it,  while  it  is  so  smooth  that  it  would  almost  glide 
through  a  pin-hole.  The  extraordinary  muscular  power 
of  the  thighs,  again,  combined  with  their  elasticity,  en- 
able it  to  perform  most  astonishing  leaps,  as  we  have 
remarked  in  a  preceding  page;  while  its  comparative 
lightness  and  the  toughness  of  its  skin  prevent  it  from 
receiving  any  injury,  from  whatever  height  it  may  fall. 
It  is  very  doubtful,  indeed,  as  it  appears  to  us,  whether 
it  observes  the  good  old  proverb  of  looking  before  it 
leaps,  for  we  have  seen  fleas  leap  from  the  bottom  of  a 
deep  pill-box,  where  they  could  riot  possibly  perceive 
whither  they  were  leaping.*  It  may  not  be  out  of 
place  here  to  mention,  that  fleas  (Pulicidce)  undergo 
similar  transformations  to  other  insects,  laying  their 
eggs  at  the  roots  of  the  hair  of  animals,  the  feathers  of 
birds,  or  in  woollen  stuffs.  These,  in  a  few  days,  pro- 
duce a  minute  whitish  grub,  which,  in  warm  weather 
changes  to  a  perfect  flea  in  about  six  weeks:  as  may 
be  verified  by  whoever  will  take  the  trouble  of  en- 
closing some  female  fleas,  which  are  always  the 
largest,  in  glass  tubes,  and  feeding  them  with  flies  or 
raw  beef,  as  was  done  by  Rosel,  De  Geer,  and  many 


Flea  magnified,  to  show  the  muscular  structure  of  the  legs. 
*  J.  R. 


PECULIAR    MOTIONS    OF    INSECTS.  393 

others.  Mr  Stephens  enumerates  no  less  than  twelve 
species,  from  which  it  appears  that  those  found  on 
the  dog,  the  pigeon,  and  other  animals,  are  quite 
different  from  the  common  flea,  and  it  is  probable 
these  will  not  readily  pass  from  their  natural  habit  to 
infest  us,  as  is  commonly  believed. 

The  extraordinary  power  of  leaping  in  grasshoppers 
and  their  congeners  is  matter  of  common  observa- 
tion. The  motion  is  effected  by  means  of  very 
strong  muscles  with  which  the  hind  thighs  are  fur- 
nished; and  it  is  a  similar  structure  which  enables  the 
frog-hoppers  (Cercopidce  LEACH),  so  common  on 
plants  during  summer,  to  perform  leaps  of  extraor- 
dinary extent,  in  which,  however,  they  have  likewise 
the  assistance  of  their  wings.  Some  species  make 
use  of  their  faculty  of  leaping  to  escape  from  their 
enemies,  as  well  as  for  the  purpose  of  changing 
place,  while  others  use  it  to  spring  upon  their  prey. 
Among  the  former  we  may  mention  a  family 
of  small  insects  (PoduridaZ)  LEACH),  some  of  them 
inhabiting  water  or  damp  places,  though  most  of  the 
species  are  found  under  decaying  bark  or  vegetable  re- 
fuse. The  one  that  is  most  likely  to  attract  attention 
is  a  very  small  gregarious  one,  the  water  spring-tail 
(Podura  aquatica),  which  may  often  be  seen,  during 
the  summer,  crowded  upon  the  rain-water  collected 
in  the  footsteps  of  cattle,  the  ruts  of  cart-wheels,  or 
by  the  edges  of  small  ponds,  and  looking  precisely 
as  if  one  had  strewed  about  a  handful  of  coal-ashes 
or  gunpowder  ;  but,  though  at  first  glance  they  .seem 
inanimated,  closer  inspection  will  show  that  they  are 
in  active  motion,  and  particularly  if  they  be  alarmed 
— leaping  about  and  upon  one  another,  and  on  the 
water,  like  so  many  minute  fire- works.  Those  which 
are  solitary  are  much  larger,  among  which  we  may 
mention  the  velvet  spring-tail  (Podura  holosericea)^ 
of  which  we  here  give  a  magnified  figure,  to  show 


394  INSECT    TRANSFORMATIONS. 

the  spring  in  the  tail,  by  means  of  which  it  leaps, 
jerking  it  downwards  and  outwards  from  its  body  as 
the  flea  does  its  legs. 


Leaping  position  of  the  velvet  spring-tail,  magnified, 

Amongst  the  insects  which  spring  upon  their  prey 
like  the  cat  and  the  lion,  the  most  commonly  observed 
is  the  little  hunting  spider  (Salticus  scenicus),  whose 
zebra  stripes  of  white  and  brown  render  it  easily- 
discovered  on  our  window-frames  and  palings.* 
But  all  the  spiders  —  even  those  which  form  webs  — •- 
are  accustomed  to  spring  in  a  similar  way  upon  what 
they  have  caught  ;  and  when  we  are  told  of  the 
gigantic  American  one  (My gale  avicularia),  which 
even  makes  prey  of  small  birds  (Trochilidce},  the 
necessity  of  extraordinary  agility  must  be  obvious  ; 
for  these  tiny  birds  are  described  to  move  with 
almost  the  velocity  of  light,  —  the  eye,  notwithstand- 
ing the  brilliancy  of  their  metallic  colours,  being 
frequently  baffled  in  tracking  their  flight.  The 
spider  itself,  however,  being  three  inches  in  length, 
one  and  a  half  in  breadth,  and  eleven  inches  in  the 
expansion  of  its  legs,  is  little  less  than  the  bird  upon 
which  it  pounces,  as  may  be  seen  from  the  following 
figure,  taken  from  the  splendid  work  of  Madame 
Merian  upon  the  insects  of  Surinam. 

All  animals  which  fly  are  furnished  with  powerful 
muscles  for  moving  their  wings,  in  the  same  way  as 
the  limbs  of  those  which  leap  are  similarly  provided; 

*  See  Insect  Architecture,  p.  355. 


PECULIAR    MOTIONS    OF    INSECTS. 


395 


Mygale  avicularia,  from  Madame  Merian. 

and  we  may,  therefore,  remark,  in  passing,  that  any 
invention  for  enabling  men  to  fly  must  take  the 
comparative  weakness  of  our  muscles  into  primary 
consideration.  Let  any  one  try  merely  to  stretch  out 
his  arm  as  a  hawk,  or  a  swift  fly  ( Volucella),  does  its 
wings,  when  hovering  apparently  motionless  in  the 
air,  —  and  the  quick  recurrence  of  weariness,  speedily 
increasing  to  pain,  will  afford  unequivocal  proof  of 
the  apparently  exhaustless  vigour  of  their  vojitant 
muscles,  compared  with  ours.  It  would  be  no  very 
difficult  matter  to  give  voluminous  illustrations  on 
this  curious  subject.  A  French  naturalist,  M.  Cha- 
brier,  has  actually  written  an  elaborate  quarto  vo- 
lume, on  the  flight  of  insects.*  Though  Chabrier 
has  unquestionable  talents  of  the  first  order  for  re- 
s  earch,  it  is  unfortunate  that  he  permits  his  fancy  to 
travel  somewhat  beyond  the  boundaries  of  fact;  and 
t  o  this,  no  doubt,  we  are  to  ascribe  his  retracting  his 

*  Essai  sur  le  Vol  des  Insectes,  4to.  Paris,  1801. 


396  INSECT    TRANSFORMATIONS. 

former  opinions  on  the  flight  of  insects;  yet  it  might 
have  been  supposed,  that  in  writing  so  voluminously 
on  the  subject,  he  had  left  no  point  uninvestigated. 
Nothing,  however,  can  be  more  praiseworthy  than 
the  candour  (not  very  common  in  such  cases)  with 
which  Chabrier  corrects  his  own  mistake. 

In  the  two-winged  flies  (Diptera)  Chabrier  de- 
scribes two  sets  of  muscular  ribbons  for  putting  the 
wings  in  play  —  the  dorsal,  placed  lengthwise,  and 
used  to  lower  the  wings,  and  the  sterno-dorsal,  placed 
obliquely  across  these  for  raising  the  wings.  In  the 
dragon-flies  (Libellulina),  again,  the  disposition  is 
somewhat  different,  the  sterna- dorsal  muscles  being 
placed  intermediate,  while  another  set  of  powerful 
muscles,  called  pectoral,  are  placed  lengthwise,  and 
are  inserted  immediately  into  the  wings.  In  his  first 
work,  our  author  thought  these  muscles  acted  sepa- 
rately, but  he  now  says  they  act  in  concert;  and  he 
is  not  now  inclined  to  ascribe,  as  he  at  first  did, 
so  much  influence  to  the  air  in  the  interior  of  the 
body,  nor  to  the  spring  of  the  harder  parts  of  the 
back  and  breast.  £  Certainly,'  he  adds,  <  the  elas- 
ticity of  these  parts,  and  the  re-action  of  the  interior 
air  have  their  use  :  the  fluid,  particularly,  contained 
in  their  numerous  vesicles,  is,  perhaps,  very  light,  and 
contributes  to  reduce  the  specific  gravity  of  the 
insect.  Besides,  by  enveloping  the  interior  organs, 
it  appears  to  me  intended  to  protect  these  against 
the  violent  motions  of  flight,  and  to  contribute  to 
the  expansion  of  the  chest,  dilating  immediately 
after  being  compressed  by  the  contraction  of  the 
muscles  in  the  act  of  raising  the  wings. '* 

It  will  appear,  from  this  brief  abstract,  that  the 
subject  is  not  a  little  interesting;  yet  it  is  not  so  easy 
to  throw  it  into  a  form  likely  to  be  understood  by  a 
general  reader.  Flying  with  wings,  however,  is  a 

*  M.  Chabrier  in  Ann.  des  Soc.  Nat.,  Avril  1829,  p.  505. 


PECULIAR    MOTIONS    OF    INSECTS. 


397 


Magnified  views  of  the  muscular  ribbons  for  moving  the  wings 
in  Syrphus  inanis.  «,  part  of  the  belly.  6,  the  costo  dorsal 
muscles,  c,  d,  the  sterna  dorsal,  e,  part  of  the  head. 

less  difficult  subject  of  investigation  than  flying  with- 
out wings,  as  is  practised  by  the  gossamer  spider 
(Jlranea  obtextrix,  BECHSTEIN),  and  its  congeners. 
We  do  not  allude  merely  to  the  threads  carried  out 
from  a  spider  by  a  current  of  air,  till  it  is  fixed  and 
forms  a  bridge,  along  which  the  creature  can  pass, 
nor  to  the  similar  lines  which  are  left  to  float  freely, 
in  the  case  of  the  gossamer,  without  attachment* 
We  refer  to  the  power  which  the  spider  apparently 
possesses  of  directing  its  flight.  Let  any  one  endea- 
vour to  catch  one  of  the  spiders  which  may  frequently 
be  seen  dropping  from  the  ceiling  of  a  room,  the 
branch  of  a  tree,  or  other  elevated  object,  and  he  will 
find  it  no  easy  task  to  lay  hold  of  the  little  web  spin- 

*  See  Insect  Architecture,  pp.  339-54. 
VOL.   vi.  34 


398  INSECT    TRANSFORMATIONS.    . 

ner,  for  it  will  not  only  drop  perpendicularly  by 
spinning  a  longer  thread  (it  seldom  tries  to  escape 
by  remounting),  bu.t  it  will  swing  itself  away  from  the 
approaching  hand,  in  a  manner  which  it  seems  not  a 
little  difficult  to  comprehend,  for  it  does  not  move  a 
limb  to  produce  an  impulse  in  the  air,  as  the  diving 
spider  (Jlrgyroneta  aquatica)  does  when  it  moves 
through  the  water.  In  instances  when  no  escape  is 
intended,  when  spiders,  even  of  considerable  size, 
drop  from  a  height,  we  have  often  seen  them  swing 
out  of  the  perpendicular  without  any  apparent  aid 
from  the  wind.  It  is  highly  probable  that  this 
movement  is  effected  by  some  internal  apparatus 
analogous  to  the  swim-bladder  of  fishes;  but  at 
present  we  are  not  aware  that  anything  beyond  con- 
jecture has  been  published  upon  the  subject..  We 
may  state,  however,  that  they  cannot  in  this  manner 
move  far. 


Syrphus. 


CHAPTER  XVII. 

Rest  of  Insects.. 

MR  BRIGHTWELL  is  reported  to  have  once  ob- 
served an  individual  living  specimen  of  Haltica  con- 
cinna,  which  appeared  to  remain  motionless  on  the 
same  spot  of  a  wall  for  three  successive  days;*  but 
though  this  is  given  as  something  unusual,  we  have 
made  similar  observations  in  the  case  of  numerous  in- 
sects of  all  orders  and  families.  The  continual  sta- 
tionary appearance,  however,  is,  in  most  of  guch  cases, 
quite  fallacious.  To  use  a  familiar  illustration,  we 
might  as  well  think  the  snail  stationary  which  we  see 
every  day,  perhaps  for  weeks  together,  coiled  up  in 
the  same  niche  of  the  garden-wall,  as  if  it  were  glued 
to  the  spot,  and  had  never  moved  from  it  a  hair's- 
breadth,  —  were  it  not  that  the  depredations  committed 
upon  a  contiguous  lettuce,  prove  that  it  does  not 
always  sleep,  though  its  excursions  from  its  chosen 
niche,  as  they  take  place  only  at  night,  are  seldom,  if 
ever,  observed.  Like  a  very  large  portion  of  the 
whole  insect  world,  snails  always  sleep  throughout 
the  day,  unless  roused  by  an  accidental  shower  of  rain, 
which  tempts  them  to  banquet  on  the  refreshed 
herbage.  Upon  butterflies,  and  some  other  day  in- 
sects, again,  the  occurrence  of  rain  or  cloudy  weather 
usually  operates  like  a  continuance  or  a  renewal  of 
night;  and  this  seems  to  happen  even  in-doors,  where 
the  air  is  warm  and  comparatively  dry.  We  had  a 
female  of  the  brimstone  butterfly  (Gonepteryx 
Jthamni)  in  our  study,  which  we  were  desirous  of 

*  Kirby  and  Spence,  Intr.,  vol.  iv,  p.  193. 


400  INSECT    TRANSFORMATIONS. 

having  deposite  her  eggs  on  a  plant  of  the  buckthorn 
(Rhamnus  frangula),  which  we  had  placed  in  a 
garden-pot  for  this  purpose;  and  we  remarked  that 
she  manifested  no  inclination  to  move  from  the  same 
leaf,  except  for  an  hour  or  two  in  the  forenoon,  and 
when  it  was  damp  or  cloudy,  not  even  then.  If 
disturbed  in  her  repose,  she  would  fall  down  as  if  life- 
less, and  continue  her  sleep  —  (if  sleep  it  was),  without 
being  awakened  by  the  fall,  till  her  regular  period  of 
animation  returned. 

We  have  used  the  qualifying  phrase  —  <  if  sleep  it 
was;'  because  the  rest  of  insects,  though  correspond- 
ing, in  the  circumstance  of  remaining  without  motion, 
with  the  sleep  of  the  larger  animals,  may  not  agree 
in  any  other  respect,  —  and  particularly  in  the  qui- 
escence of*the  senses.  In  the  important  point  of 
the  state  of  the  brain,  it  does  not  appear  how  there 
could  be  any  agreement  in  the  phenomenon;  as  may 
be  inferred  from  comparing  the  structure  of  insects, 
as  respects  their  nerves  and  blood-vessels,  with  that 
of  man. 

Insects,  though  possessed  of  nerves,  have  nothing 
similar  to  our  brain  and  spinal  cord,  the  two  sources 
of  our  nerves  of  feeling  and  of  motion,  as  so  beauti- 
fully explained  by  the  recent  discoveries  of  Mr  Charles 
Bel).  Instead  of  this,  they  have  a  chain  of  what  are 
called  ganglia,  or  bundles  of  nervous  substance,  and 
from  each  of  these  bundles  nerves  branch  out  to  the 
parts  contiguous,  —  each  ganglion  forming  the  centre 
of  feeling  to  the  parts  to  which  its  nerves  run;  and 
hence  it  is  that  insects  will  live,  and  (so  far  as  we 
can  perceive)  feel  comparatively  little  general  pain 
and  inconvenience  from  the  loss  of  their  limbs  or 
even  of  their  heads.  Thus  the  tail  of  a  wasp  or  a 
bee  will  sting  long  after  it  is  severed  from  the  body, 
and  the  head  of  a  dragon-fly  will  eat  as  voraciously 
after  it  is  cut  ofF;  as  if  it  had  to  supply  an  insatiable 


HEST    OF    INSECTS.  401 

stomach,  —  phenomena  easily  accounted  for  from  the 
want  of  a  brain,  and  from  each  ganglion  having  its 
own  set  of  nerves.  This  may  be  better  understood  by 
looking  at  the  central  chain  of  ganglia  in  the  larva  of 
the  day-fly  before  figured.* 

Insects  again  differ  from  man  in  having  no  heart 
nor  circulating  blood,  at  least  so  far  as  has  hitherto 
been  discovered. f  Dr  Carus,  of  Dresden,  is,  indeed, 
at  present  endeavouring  to  establish  a  claim  to  the  dis- 
covery of  the^  circulation  of  the  blood  in  insects ;  but 
this  circulation,  which  is  most  probably  only  partial, 
has,  we  think,  been  observed  by  naturalists  of  a  former 
age.  £  De  Geer,'  say  Kirby  and  Spence,  '  whose 
love  of  truth  and  accuracy  no  one  will  call  in 
question,  saw  the  appearance  of  blood-vessels  in 
the  leg  of  the  larva  of  a  caddis  fly  (Phryganea, 
LINN.),  as  Lyonnet  did  in  those  of  a  flea,J  and  in 
the  transparent  thigh  of  the  bird  fly  ( Ornithomyia, 
avicularia)  he  discovered  a  pulse  like  that  of  an 
artery.^  Baker,  whose  only  object  was  to  record 
what  he  saw,  speaks  of  the  current  of  the  blood 
being  remarkably  visible  in  the  legs  of  some  small 
bugs;||  what  he  meant  by  that  term  is  uncer- 
tain, but  they  could  not  be  spiders,  which  he  had 
just  distinguished.  This  author  has  likewise  seen 
a  green  fluid  passing  through  the  vessels  of  the  wings 
of  grasshoppers  ;TT  and  M.  Chabrier  is  of  opinion 
that  insects  possess  the  power  of  propelling  a  flujd 
into  the  nervures  of  their  wings,  and  withdrawing  it 
at  pleasure,  as  they  are  elevated  or  depressed;**  but 

*  See  page  139. 

t  See  Cuvie'r,  Anat.  Comp.  vol.  iv,  p.  478,  &c.     And  Mar- 
cel de  Serres,  Mem.  du  Mus.  pour  1819. 
£  Lesser,  vol.  ii,  p.  84,  note. 
§  De  Geer,  vol.  ii,  p.  505;  vol.  vi,  p.  287. 
I!  On  the  Microscope,  vol.  i,  p.  130.  TT  Ibid. 

**  Sur  le  Vol  des  Insectes. 
VOL.   vi,  34* 


402  INSECT    TRANSFORMATIONS. 

these  two  last  facts  must  be  accounted  for  on  other 
principles,  as  there  is  clearly  no  circulation.'* 

The   statement  recently  published  by  one  of  these 
authors    (Mr    Spence),    respecting  the  alleged    dis- 
covery of  insect  circulation  by  Dr  Carus,  is  founded 
on    facts    which  were  shown  and  explained   to   him 
by    the   doctor    himself.       <  The    first   insect,'    says 
Mr    Spence,    c  to    which    Dr    Carus    directed   my 
attention,  was  the  larva  of  ephemera  vulgata  (or  an 
allied  species),  in   which,  near  to  the  bronchioe  and 
parallel  with  each  side  of  the  body,  was  very  distinctly 
visible   a  constant  current,  towards  the  tail,  of  oblong 
globules  swimming  in   a  transparent   fluid,  propelled 
with  a  regular  pulsating  motion;  and  on  cutting  the 
body  of  the   larva  across  near  the  tail,  three  globules 
were    most    plainly    seen  pushed    out  of  the  divided 
vessels  in  a  distinct  mass,   which  increased  at  each 
pulsation.      I  cannot  express  the  pleasure   which   it 
gave  me,  to  see  thus  clearly  this  ocular  demonstra- 
tion of  one  of  the  most  important  physiological  dis- 
coveries of  modern  times;  and  my  gratification  was 
heightened  by  the  next  object  which  Dr  Carus  placed 
before  his  microscope,  viz,  —  a  specimen  of  semblis 
viridis    (the    green  lace-winged  fly,)  in  which  pre- 
cisely the  same   phenomena,   but,    if  possible,  more 
clearly,  were  seen  in  the  nervures  of  the  wings  and 
in  the   antennae,  in  both  which  the  constant  current 
of  globules  was  most  apparent;  and  in   the   former, 
the  sudden  turning  of  these  globules,  at  the  apex  of 
the  wing,  out  of  the  exterior  nervure  into  a  central 
one,  with  which  it  joins  and  forms  an  acute  angle, 
was  equally  curious  and  striking.     On  cutting  off  the 
end  of  the  antennae,  precisely  the  same  emission  of 
globules  (which  soon   assume  a  greenish  tint)  took 
place   as  in  the  former  case,  forming  a  mass,  which 
was  increased  with  a  sudden  gush  at  each  pulsation. 

*  Introd.  vol.  iv,  p,  86. 


REST    OF    INSECTS.  403 

Dr  Cams  has  observed  the  same  phenomena  in  the 
wings  of  Semblis  bilineata,  and  in  the  elytra  (wing 
cases)  of  Lampyris  noctiluca  (the  glow  worm),  and 
L.  Italica,  as  well  as  in  the  fin-like  appendages  at  the 
tail  of  the  larva  of  Jlgrion  puella  (the  damsel  dragon 
fly),  in  which  he  first  made  the  discovery^  and  in 
which  the  circulation  is  remarkably  distinct.'* 

We  apprehend,  as  far  as  we  can  collect  from  this 
description,  that  the  alleged  discovery  of  Dr  Carus 
does  not  advance  a  step  in  demonstrating  a  circu- 
lation in  insects  similar  to  that  of  other  classes  of 
animals;  for  it  is  to  be  recollected,  that  the  dorsal 
vessel,  the  only  organ  in  insects  analogous  to  a 
heart,  although  it  pulsates  irregularly,  has  no  ap- 
parent arteries  or  veins  connected  with  it:  and 
therefore  the  impulsions  described  by  De  Geer,  the 
current  mentioned  by  Baker,  and  the  phenomena 
exhibited  by  Carus,  furnish  no  proof  whatever  of 
a  general  circulatory  system,  though  they  appear  to 
indicate  local  movements  in  the  fluids  of  insects, 
agreeably  to  the  original  views  of  Qhabrier,  or  those 
of  Swammerdam  formerly  quoted. f 

It  may  appear  to  some,  that  the  preceding  has  but 
a  very  remote  connexion  with  the  subject  immediately 
before  us;  but  we  shall  presently  show  its  con- 
nexion with  the  phenomena  of  insect  sleep.  We 
agree  with  Professor  Blumenbach,  that  sleep  in  man 
most  probably  consists  in  a  diminished  or  impeded 
flow  of  arterial  blood  into  the  brain.  For  example, 
if,  by  cold  feet,  a  fit  of  passion,  or  a  heavy  supper, 
a  gush  of  blood  is  forced  into  the  brain  and  stag- 
nates there,  the  consequence  will  be  the  snoring 
death-like  sleep  of  apoplexy;  and  the  same  will 
happen,  if  a  blow  on  the  head,  or  a  fever,  throws 
a  quantity  of  blood  upon  the  brain.  Blumenbach 

*  Spence  in  Mag.  of  Nat  Hist,  Jan.  18SO,  p.  49, 
t  See  page  343. 


404  INSECT    TRANSFORMATIONS. 

had  ocular  demonstration  of  the  fact  contended  for, 
with  respect  to  the  diminished  flow  of  blood,  in  a 
man  whose  brain  was  exposed  by  the  accidental  re- 
moval of  a  part  of  the  skull;  for,  whenever  this  man 
fell  asleep,  the  brain  was  seen  to  shrink  and  subside, 
but  the  moment  he  awoke  a  tide  of  blood  was  seen 
rushing"  through  the  vessels  and  swelling  the  brain. 
The  same  is  also  proved  by  the  fact>  that  in  madness 
and  inflammation  of  the  brain,  when  the  blood  flows 
rapidly,  the  unhappy  sufferer  is  altogether  deprived 
of  sleep,  unless  the  current  of  the  blood  is  retarded 
by  strong  doses  of  opium,  or  by  taking  away  a  large 
quantity  by  the  lancet.  It  will  follow,  that  when  the 
blood-vessels  of  the  brain  are  gorged,  as  well  as  when 
they  are  not  sufficiently  full,  —  sleep  will  be  equally 
produced.  Force  more  blood  into  the  brain  than  can 
find  room  to  flow,  and  drowsiness,  sleep,  perhaps 
apoplexy,  will  follow;  —  diminish  the  quantity,  so  that 
it  may  lack  force  to  keep  up  the  current,  and  sleep 
will  also  come  on.  *On  these  principles  it  is  that 
thinking,  by  bestirring  the  brain  and  driving  thither  a 
brisker  current  of  blood,  prevents  sleep;  while, 
bathing  the  feet  in  warm  water,  eating  a  moderate 
supper,  or  rubbing  the  body  with  a  flesh-brush,  by 
drawing  a  superabundance  of  blood  to  the  feet,  to  the 
stomach,  or  to  the  skin,  will  cause  sleep.  Again,  it 
is  a  general  law  of  animated  nature,  for  rest  to  suc- 
ceed fatigue,  as  temporary  insensibility  succeeds  vivid 
sensations.  The  pain  of  a  burn,  for  example,  comes 
and  goes  alternately;  and  by  holding  out  the  'arm 
from  the  body,  the  feeling  of  fatigue  and  pain  soon 
become  so  insupportable,  that  rest  cannot  be  dis- 
pensed with.  Sleep,  then,  seems  to  be  a  general 
consequence  of  this  rest  after  fatigue. 

With  regard  to  insects,  it  is  evident  that  many  of 
the  above  facts  will  not  at  all  apply;  for  as  insects 
have  neither  a  heart  nor  a  brain,  their  sleep  cannot 


REST    OF    INSECTS.  405 

be  proximately  caused  by  a  retarded  current  of  blood. 
We  want  data  also  for  determining  whether  similar 
effects  are  produced  upon  the  senses  of  insects  during 
their  quiescence,  or  apparent  sleep,  as  take  place  in 
ourselves.  The  shutting  of  the  eye-lids,  next  to 
motionless  rest,  is  one  of  the  most  obvious  charac- 
teristics of  sleep  in  man  ;  but  in  insects  nothing  like 
this  can  be  observed,  because  they  have  nothing 
analogous  to  eye-lids.  The  senses  of  insects,  indeed, 
may  not  sleep  at  all  —  and  what  renders  this  the  more 
probable  is,  that  in  the  case  of  gnats,  crane-flies 
(Tipulidcc),  moths,  butterflies,  &c,  however  long  they 
may  have  been  observed  to  be  quiescent,  or  sleeping, 
in  the  same  place,  they  are  instantly  on  the  alert  at 
the  approach  of  danger,  though  no  noise  be  made  to 
alarm  them.*  It  may  serve  to  illustrate  this  state  of 
wakefulness  in  the  senses  of  quiescent  insects,  that 
the  senses  in  man  do  not  all  sleep  in  the  same  degree 
of  profundity.  This  very  curious  fact  was  first,  we 
believe,  observed  by  M.  Cabanis,  who  also  found 
that  some  of  our  senses  and  members  go  to  sleep 
sooner  than  others  —  in  proportion,  it  may  be  pre- 
sumed to  their  fatigue  from  their  waking  exertions, 
and  to  the  flow  of  blood  through  them.  According 
to  Cabanis,  then,  the  muscles  of  the  legs  and  arms 
are  the  first  to  become  drowsy,  and  next  those  that 
sustain  the  head,  which,  losing  its  support,  falls  for- 
ward ;  the  muscles  of  the  back  follow,  and  it  becomes 
bent.  Among  the  senses,  the  eye  is  the  first  that 
goes  to  sleep  ;  and  after  it  the  smell,  taste,  hearing, 
and  touch,  become  drowsy  in  succession.  The  sense 
of  touch  never  sleeps  so  profoundly  as  the  others,  — 
a  fact  inferred  from  our  frequent  change  of  position 
during  sleep,  which  must  be  the  consequence  of 
uneasy  sensations  of  touch.  Besides  this,  it  is  well 
known  that  a  slight  tickling  of  the  soles  of  the  feet 

*  J.  R. 


406  INSECT    TRANSFORMATIONS. 

will  waken  a  person  whom  no  noise  could  rouse.  In 
the  order  of  their  awaking  again,  taste  and  smell  are 
always  last,  and  sight  appears  more  difficult  to  awaken 
than  hearing  ;  for  a  slight  noise  will  often  rouse  a 
sleep-walker,  who  had  borne  an  intense  light  on  his 
unshut  eyes,  without  seeming  in  the  least  to  feel  its 
influence.* 

The  torpidity  of  insects  during  winter,  which  in 
some  of  its  circumstances  is  analogous  to  sleep,  will 
require  the  less  to  be  discussed  here,  that  we  have, 
under  our  three  former  divisions  of  Eggs,  Pupae,  and 
Larvae,  considered  it  very  amply.  The  number  of 
insects,  indeed,  which  hybernate  in  the  perfect  state 
are  comparatively  few.  Of  the  brimstone  butterfly 
(Gonepteryz  Rhamni),  Mr  Stephens  tells  us  the  se- 
cond brood  appears  in  autumn,  '  and  of  the  latter,' 
he  adds,  c  many  individuals  of  both  sexes  remain 
throughout  the  winter,  and  make  their  appearance  on 
the  first  sunny  day  in  spring.  I  have  seen  them 
sometimes  so  early  as  the  middle  of  February,  '"j* 
The  commonly  perfect  state  of  the  wings  in  such 
cases  might,  we  think,  lead  to  the  contrary  con- 
clusion, that  the  butterfly  has  just  been  evolved 
from  its  chrysalis.  Several  other  species,  however, 
chiefly  of  the  genus  Vanessa,  do  live  through  the 
winter  in  the  perfect  state  ;  but  this,  as  far  as  ge- 
neral observation  extends,  can  only  be  affirmed 
of  the  female.  Yet  will  insects  bear  almost  incre- 
dible degrees  of  e£>ld  with  impunity.  Out  of  the 
multiplicity  of  instances  of  this  on  record  we  shall 
select  two.  In  Newfoundland,  Captain  Buchan  saw 
a  lake,  which  in  the  evening  was  entirely  still  and 
frozen  over,  but  as  soon  as  the  sun  had  dissolved  the 
ice  in  the  morning,  it  was  all  in  a  bustle  of  anima- 
tion, in  consequence,  as  was  discovered,  of  myriads 

*  Cabanis,  Rapports  du  Physique  et  Moral, 
t  Illustrations,,  vol.  i,  p.  9. 


REST    OF    IIs SECTS.  407 

of  flies  let  loose,  while  many  still  remained  <  infixed 
and  frozen  round. '  A  still  stronger  instance  is  men- 
tioned by  Ellis,  in  which  a  large  black  mass,  like 
coal  or  peat  upon  the  hearth,  dissolved,  when  thrown 
upon  the  fire,  into  a  cloud  of  mosquitoes  (Culicidce)* 
It  has  been  remarked  by  most  writers  upon  the 
torpidity  of  warm-blooded  animals,  that  cold  does 
not  seem  to  be  its  only  cause,  and  the  same  appa- 
rently holds  in  the  case  of  insects.  Bees,  indeed, 
which  remain  semi-torpid  during  the  winter,  may  be 
prematurely  animated  into  activity  by  the  occurrence 
of  some  days  of  extraordinary  mildness  in  spring  ; 
but,  what  is  not  a  little  wonderful  and  inexplicable, 
they  are  not  roused  by  much  milder  weather  when 
it  occurs  before  Christmas,  —  on  the  same  principle, 
perhaps,  that  a  man  is  more  easily  awakened  after  he 
has  slept  six  or  seven  hours  than  in  the  earlier  part 
of  the  night.  Immediately  after  the  first  severe  frost 
in  the  winter  of  1829-30,  we  dug  down  into  the 
lower  chambers  of  a  nest  of  the  wood-ant  (Formica 
rufa\  at  Forest  Hill,  Kent,  which  we  had  thatched 
thickly  with  fern-leaves  the  preceding  November,  both 
to  mark  the  spot  and  to  protect  the  ants  in  winter. 
About  two  feet  deep  we  found  the  little  colonists  all 
huddled  up  in  contiguous  separate  chambers,  quite 
motionless  till  they-  were  exposed  to  the  warm  sun- 
shine, when  they  began  to  drag  themselves  slug- 
gishly and  reluctantly  along.  Even  upon  bringing 
some  of  them  into  a  warm  room,  they  did  not  awaken 
into  summer  activity,  but  remained  lethargic,  un- 
willing to  move,  and  refusing  to  eat,  and  continued 
in  the  same  state  of  semi-torpidity  till  their  brethren 
in  the  woods  began  to  bestir  themselves  to  repair  the 
damages  caused  by  the  winter  storms  in  the  out- 
works of  their  encampments.  | 

*  Quarterly  Review,  April  1821,  p.  200,  t  J.  R. 


408  INSECT    TRANSFORMATIONS. 

The  younger  Huber  has  given  an  interesting  ac- 
count of  the  hybernation  of  ants,  which  differs  in 
some  particulars  from  what  we  have  observed  of  the 
wood-ant  ;  but  he  speaks  of  ants  in  general.  The 
subject,  indeed,  derives  importance  from  the  popular 
opinion,  that  they  amass  wheat  and  other  grain  as  a 
winter  store,  having  been  refuted  by  the  experiments 
of  Gould  and  other  accurate  observers.  *  We 
have  endeavoured,'  says  M.  Huber,  *  to  explain 
their  preservation,  by  supposing  them  to  fall  into  a 
state  of  torpor  at  this  period.  They,  in  fact,  be- 
came torpid  during  the  intense  cold,  but  when  the 
season  is  not  very  severe,  the  depth  of  their  nest 
guards  them  from  the  effects  of  the  frost  :  they  do 
not  become  torpid  unless  the  temperature  is  reduced 
to  the  second  degree  of  Reaumur  under  the  freezing 
point,  (27°  Fahrenheit.)  I  have  occasionally  seen 
them  walking  upon  the  snow,  engaged  in  their  cus- 
tomary avocations.  In  so  reduced  a  temperature, 
they  would  be  exposed  to  the  horrors  of  famine, 
were  they  not  supplied  with  food  by  the  pucerons, 
who,  by  an  admirable  concurrence  of  circumstances, 
which  we  cannot  attribute  to  chance,  become  torpid 
at  precisely  the  same  degree  of  cold  as  the  ants,  and 
recover  from  this  state  also  at  the  same  time  :  the 
ants,  therefore,  always  find  them  when  they  need 
them. 

'  Those  ants  that  do  not  possess  the  knowledge  of 
the  mode  of  assembling  these  insects,  are,  at  least, 
acquainted  with  their  retreat  ;  they  follow  them  to  the 
feet  of  the  trees  and  the  branches  of  the  shrubs  they 
before  frequented,  and  pass  at  the  first  degree  of  frost 
along  the  hedges,  following  the  paths  which  con- 
duct to  these  insects.  They  bring  back  to  the  re- 
public a  small  quantity  of  honey ;  a  very  little  sufficing 
for  their  support  in  winter.  As  soon  as  the  ants 
recover  from  their  torpid  state,  they  venture  forth  to 


HEST    OF    INSECTS,  409 

procure  their  food.  The  aliment  contained  in  their 
stomach  is,  on  their  return,  equally  distributed  to 
their  companions.  These  juices  scarcely  evaporate, 
during  this  season,  owing  to  the  thickness  of  the 
honey  rings  investing  the  body.  1  have  known  ants 
preserve,  during  a  considerable  time,  their  internal 
stock  of  provisions,  when  they  could  not  impart  it  to 
their  companions.  When  the  cold  increases  in  a 
gradual  manner,  (and  this  is  commonly  what  the 
ants  experience,  who  are  screened  from  it  by  a  thick 
wall  of  earth,)  they  collect  and  lie  upon  each  other 
by  thousands,  and  appear  all  hooked  together.  Is 
this  done  in  order  to  provide  themselves  a  little  heat  ? 
I  presume  this  to  be  the  case,  but  our  thermometers 
are  not  sufficiently  delicate  to  indicate  if  this  be  really 
the  fact.5* 

During  the  frosts  of  1829-30,  we  opened  two 
nests  of  the  yellow  ant  (Formica  flav a),  in  which  we 
found  the  inhabitants  by  no  means  torpid  or  inactive, 
although  not  so  lively  as  in  summer  ;  but  these 
nests  were  in  a  peculiarly  warm  situation,  being  both 
in  the  old  trunks  of  willows,  rendered  quite  spongy 
by  the  dry-rot,  and  facing  the  south-west,  where  they 
had  the  benefit  of  every  glimpse  of  sunshine.  We 
searched  with  great  minuteness  for  the  eggs  of  the 
aphides  mentioned  by  Huber,  but  without  success, 
and  we  cannot  account  for  their  means  of  subsist- 
ence, unless  they  fed  on  the  various  insects  and  crus- 
taceous  animals  which  abounded  in  the  trees, 
(Onisci,  Julidce,  &c.)  They  were  also,  in  both  in- 
stances, within  a  yard  of  a  stream  of  water,  to  the 
vicinity  of  which  we  have  observed  that  this  species 
is  partial,  and  it  is  not  improbable  that  it  may  form 
an  indispensable  part  of  their  subsistence.  No  spe- 
cies of  ants,  indeed,  can  live  without  drinking.  In 
February  of  the  same  year,  immediately  after  the 

*  Huber  on  Ants,  p.  239,     See  also  this  volume,  pages  113-116. 
VOL,   vj.  35 


410  INSECT    TRANSFORMATIONS. 

breaking  up  of  the  first  frost,  we  also  observed  num- 
bers of  the  small  black  ant  (Formica  fusca)  running 
about  the  sunny  sides  of  hedge-banks  ;  and  though 
we  did  not  trace  them  to  their  winter  quarters,  we 
think  it  not  improbable,  from  their  very  early  appear- 
ance, that  they  had  never  been  completely  torpid.* 

The  bee  is  popularly  believed  to  hybernate,  the 
seven  winter  sleepers  being  said  to  be,  *  the  bat,  the 
bee,  the  butterfly,  the  cuckoo,  and  the  three  swallows;' 
but,  like  many  of  the  popular  notions  on  natural  his- 
tory, this  is  almost  wholly  erroneous,  for  at  least,  out 
of  these  seven,  the  four  birds  certainly  do  not  become 
torpid.  With  respect  to  the  bee,  again,  we  find  some 
of  the  most  distinguished  observers  at  variance. 
Reaumur  is  an  advocate  for  the  popular  opinion. 
c  It  has  been  established,'  he  says,  '  with  a  wis- 
dom, which  we  cannot  but  admire,  —  with  which 
everything  in  nature  has  been  made  and  ordained,  — 
that  during  the  greater  part  of  the  time  in  which  the 
country  furnishes  nothing  to  bees,  they  have  no 
longer  need  to  eat.  The  cold  which  arrests  the  ve- 
getation of  plants  —  which  deprives  our  fields  and 
meadows  of  their  flowers  —  throws  the  bees  into  a 
state  in  which  nourishment  ceases  to  be  necessary  to 
them  ;  it  keeps  them  in  a  sort  of  torpidity,  in  which 
no  transpiration  from  them  takes  place,  or  at  least 
during  which  the  quantity  of  what  transpires  is  so 
inconsiderable,  that  it  cannot  be  restored  by  aliment 
without  their  lives  being  endangered.  In  winter, 
while  it  freezes,  we  may  observe  without  fear  the  in- 
terior of  hives  that  are  not  of  glass  ;  for  we  may  lay 
them  on  their  sides,  and  even  turn  them  bottom 
upwards,  without  putting  any  bee  into  motion.  We 
see  the  bees  crowded  and  closely  pressed  one  against 
the  other  ;  little  space  then  suffices  for  them.'!  — 
Again,  when  mentioning  the  custom  of  putting  bee- 

*  J.  K.  t  Mem.  v.  p.  667. 


REST    OF    INSECTS.  411 

hives  during  the  winter  into  out-houses  and  cellars, 
he  says,  '  that  in  such  situations,  the  air,  though 
more  temperate  than  out  of  doors,  during  the  greater 
part  of  the  winter,  is  yet  sufficiently  cold  to  keep  the 
bees  in  that  species  of  torpidity  which  does  away 
with  the  necessity  of  their  eating.'*  He  also  says, 
positively,  that  the  milder  the  weather,  the  more  risk 
there  is  of  the  bees  consuming  their  honey  before  the 
spring,  and  dying  of  hunger  ;  confirming  his  posi- 
tion by  an  account  of  a  striking  experiment,  in 
which  a  hive  that  he  transferred  during  winter  into 
his  study,  where  the  temperature  was  usually,  in  the 
day,  10°  or  12°  of  Reaumur's  thermometer  above 
freezing,  or  59°  Fahrenheit,  though  the  bees  were  pro- 
vided with  a  plentiful  supply  of  honey,  that  if  they 
had  been  in  a  garden  would  have  served  past  the 
end  of  April,  had  consumed  nearly  their  whole  stock 
before  the  end  of  February. | 

But  the  elder  Huber  records  some  observations 
directly  opposed  to  these,  affirming  unequivocally, 
that,  so  far  from  being  torpid  in  winter,  the  heat  in  a 
well  peopled  hive  is  as  high  as  25°  Reaumur,  or  86° 
Fahrenheit,  even  when  the  thermometer  in  the  open 
air  is  several  degrees  below  zero,  the  heat  thus  ob- 
served being  generated  in  the  hive  by  their  clustering 
together,  and  keeping  themselves  in  motion  ;  and 
even  in  the  middle  of  winter  they  may  be  heard 
buzzing  as  they  always  do  when  ventilating  the 
hive,  —  a  process  which  appears  to  have  been  origi- 
nally discovered  by  Huber,  and  of  which,  on  account 
of  its  connexion  with  the  disputed  question  before  us, 
we  shall  give  his  own  description  : 

f  During  fine  weather,'  (in  summer),  says  he,  '  a 
certain  number  of  bees  always  appear  before  the  en- 
trance of  the  hive  occupied  in  vibrating  their  wings, 
but  still  more  are  found  to  be  engaged  in  ventilating 

*  Mem.  vol.  v,  p.  6S2.  t  Ib.  vol.  v,  p.  668. 


412  INSECT    TRANSFORMATIONS. 

the  interior.  The  ordinary  place  of  ventilation  is  on 
the  board  ;  those  outside  of  the  entrance  have  their 
heads  towards  it ;  those  within  have  them  in  the  oppo- 
site direction. 

*  We  may  affirm  that  they  arrange  themselves  re- 
gularly to  ventilate  more  at  ease,  thus  forming  files, 
which  terminate  at  the  entrance,  and  sometimes  dis- 
posed like  so  many  diverging  rays.       This  order  is 
not   uniform,  but  is  probably  owing  to  the  necessity 
for  the  ventilating    bees  giving  way  to  those    going 
and   coming,  whose   rapid   course  compels   them  to 
range  themselves  in   a  file,  to  avoid  being  hurt  or 
overthrown  every  instant. 

£  Sometimes  above  twenty  bees  ventilate  at  the- 
bottom  of  a  hive,  at  other  times  their  number  is 
more  circumscribed,  and  their  employment  of  various 
duration.  We  have  seen  them  engaged  in  it  during 
twenty-five  minutes,  only  taking  breath,  as  it  were, 
by  the  shortest  interruption  of  the  vibration.  On 
ceasing,  they  are  succeeded  by  others,  so  that  there 
is  never  any  intermission  of  the  buzzing  of  a  popu- 
lous hive. 

f  If  under  the  necessity  of  ventilating  during 
winter,  being  then  united  near  the  centre  of  the  mass 
towards  the  top  of  their  dwelling,  doubtless  the  bees1 
perform  this  important  function  among  vacuities  of 
the  irregular  combs,  where  there  is  room  for  their 
wings  to  expand,  as  at  least  half  an  inch  is  requisite 
for  them  to  play  freely. 

*  The    ventilation    of   the    bees,    or   the    buzzing 
which  denotes  it,   seems  to  me  more  active  during 
winter  than  at  any  other  time.     It  was  easy  to  prove 
that  this  operation   established  a  current   of  air  ;  for 
anemometers  of  light  paper  or   cotton,    hung   by    a 
thread,  were  impelled  towards  the   entrance   and  re- 
pelled from  it  with  equal  rapidity.       The  action  on 
them    never  was  entirely   interrupted,  and  its    force 


REST    OF    INSECTS.  413 

appeared  proportional  to  the  number  of  bees  fanning 
themselves. 

*  If  some  cultivators  of  bees  shut  up  the  entrance  of 
their  hives  in  winter  without  prejudice  to  the  bees,  it 
must  be  considered  that  the  air  will  penetrate  through 
the  straw  composing  them.  I  confided  an  experiment 
on  this  to  M.  Burnens,  then  at  a  distance  from  me. 
Having  closed  down  a  very  populous  straw  hive  fast 
on  its  board,  he  found  that  a  piece  of  the  finest  paper, 
suspended  by  a  hair  before  the  entrance,  oscillated 
above  an  inch  off  the  perpendicular  line.  He  poured 
liquid  honey  through  an  opening  in  the  top,  when  a 
buzzing  soon  began,  and  a  tumult  increasing  within, 
several  bees  departed.  The  oscillations  now  became 
stronger  and  more  frequent.  His  experiments  were 
made  at  three  o'clock,the  sun  shining  and  the  thermo- 
meter in  the  shade  standing  at  44V* 

Swammerdam  also  seems  to  indicate  that  bees  re- 
main active  during  the  winter,  and  in  order  to  enable 
them  to  bear  its  inclemency,  they  both  fortify  their  hive 
and  provide  a  store  of  honey.  '  The  order,'  he  says, 
'  in  which  bees  that  live  in  the  winter  months  conduct 
themselves  is  this :  they  first  open  the  cells  and  eat  the 
honey  deposited  in  the  lowest  part  of  the  hive,  ascend- 
ing by  degrees  to  the  upper  parts.  This  they  do  in 
order  to  preserve  a  mutual  warmth  between  them;  and 
the  female  deposits  her  eggs  in  the  little  cells  as  they 
are  emptied.  Therefore  I  discovered  both  stock  and 
nymphs  about  the  beginning  of  March.  Let  no  one 
be  surprised  at  this,  since  towards  the  beginning  of 
August  I  have  seen  some  thousand  eggs  enclosed  in 
the  ovary  of  a  female  bee;  so  that  it  is  natural  for  the 
bees  at  any  time  of  the  year  to  lay  their  eggs  and  in- 
crease their  family.'')" 

*  Hiiber  on  Bees,  p,  295.  t  Book  of  Nature,  i,  160, 


414  INSECT   TRANSFORMATIONS. 

John  Hunter,  whose  authority  stands  as  high  as  any 
on  record,  found  a  hive  to  grow  lighter  in  a  cold  than 
in  a  warm  week  of  winter,  and  that  a  hive,  from  Novem- 
ber 10th  till  February  9th,  lost  more  than  four  pounds 
in  weight,*  a  loss  which  could  not  well  be  ascribed  to 
evaporation. 

These  discrepancies  among  naturalists  so  distin- 
guished as  both  shrewd  and  faithful  observers,  forbid 
us,  we  think,  to  come  to  any  decided  conclusion  on  the 
subject,  till  further  researches  and  experiments  have 
been  made.  It  is  not  improbable,  however,  that  the 
truth  lies  in  the  middle  between  the  two  extremes, — 
for  it  is  quite  accordant  with  what  we  know  both  of  in- 
sects and  other  animals,  that  a  .high  degree  of  cold 
should  render  them  torpid,  while  they  may  continue 
active  if  there  should  be  a  sudden  degree  of  warmth. 
The  following  observations  by  the  ingenious  Mr  Gough, 
of  Manchester,  form  an  interesting  illustration  of  this 
curious  subject  with  respect  to  another  insect. 

*  Those,'  says  he,  '  who  have  attended  to  the  man- 
ners of  the  hearth  cricket  (Acheta  domesiica)  know 
that  it  passes  the  hottest  part  of  the  summer  in  sunny 
situations,  concealed  in  the  crevices  of  walls  and  heaps 
of  rubbish.  It  quits  its  summer  abode  about  the  end 
of  August,  and  fixes  its  residence  by  the  fireside  of 
kitchens  or  cottages,  where  it  multiplies  its  species,  and 
is  as  merry  at  Christmas  as  other  insects  in  the  dog- 
days.  Thus  do  the  comforts  of  a  warm  hearth  afford 
the  cricket  a  safe  refuge,  not  from  death,  but  from  tem- 
porary torpidity,  which  it  can  support  for  a  long  time, 
when  deprived  by  accident  of  artificial  warmth.  —  I  came 
to  the  knowledge  of  this  fact,'  continues  Mr  Gough, 
*  by  planting  a  colony  of  these  insects  in  a  kitchen, 
where  a  constant  fire  was  kept  through  the  summer,  but 

*  Phil.  Trans,  for  1790,  p.  161. 


REST    OF    INSECTS.  415 

which  is  discontinued  from  November  till  Juney  with 
the  exception  of  a  day  once  in  six  or  eight  weeks.  The 
crickets  were  brought  from  a  distance,  and  let  go  in 
this  room,  in  the  beginning  of  September  1806;  here 
they  increased  considerably  in  the  course  of  two  months, 
but  were  not  heard  or  seen  after  the  fire  was  removed. 
Their  disappearance  led  me  to  conclude  that  the  cold 
had  killed  them;  but  in  this  I  was  mistaken;  for  a  brisk 
fire  being  kept  up  for  a  whole  day  in  the  winter,  the 
warmth  of  it  invited  my  colony  from  their  hiding-place, 
but  not  before  the  evening;  after  which  they  continued 
to  skip  about  and  chirp  the  greater  part  of  the  following 
day,  when  they  again  disappeared;  being  compelled, 
by  the  returning  cold,  to  take  refuge  in  their  former  re- 
treats. They  left  the  chimney  corner  on  the  25th  of 
May,  1807,  after  a  fit  of  very  hot  weather,  and  revi- 
sited their  winter  residence  on  the  31st  of  August. 
Here  they  spent  the  summer  merely,  and  lie  torpid  at 
present  (January  1808)  in  the'crevices  of  the  chimney, 
with  the  exception  of  those  days  on  which  they  are  re- 
called to  a  temporary  existence  by  the  comforts  of  a 
fire.'* 

*  Reeve,  Essay  on  the  Torpidity  of  Animals,  p.  84. 


[The  subjeqfcpf  Insects  will  be  completed  in  a  Third 
Volume,  which  will  comprise  many  Miscellaneous 
Facts  that  were  not  capable  of  being  classed  under 
the  heads  of 'Insect  Architecture,'  or  l  Insect  Trans- 
formations;' with  directions  for  the  collection  and 
preservation  of  Insects  for  purposes  of  study;  and  a 
popular  account  of  the  various  Systems  of  Classifi- 
cation.] 


